Friday, September 18, 2026

414 papers cs.AI · cs.LG · cs.CL ← 2026-09-172026-09-21 →

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Highlights

When2Think: Learning Difficulty-Aware Length Control for Efficient Hybrid Reasoning Models

Highlight HF pick · 2▲Reasoning Jaejun Shim, HyunJin Kim, Young Jin Kim, JinYeong Bak Large Reasoning Models (LRMs) tend to overthink easy problems and underthink hard ones, and uniform length penalties or rigid routing save compute on easy cases at the cost of accuracy on hard ones. When2Think is a post-training framework for hybrid reasoning models that learns when to answer directly (NoThink) and when to reason at length (Think). Its core is Instance-level Difficulty-Aware Control (IDAC), a reward-shaping scheme based on pre-computed per-problem accuracy and token-usage statistics, which is combined with verifier rewards and batch-standardized advantages for stable critic-free optimization. On AIME24, Pass@3 rises by 10.0% while token usage falls by 27.9% relative to the base model, and on AIME25 it reaches 40.0% Pass@3, beating compression and routing-only baselines.

Large reasoning models overthink easy problems and underthink hard ones, and uniform length penalties or rigid Think/NoThink routing buy token savings on easy instances at the cost of accuracy on hard ones (the "efficiency tax"). When2Think recasts this as per-instance compute allocation, training a single hybrid policy to decide both whether to reason and how long, using offline difficulty statistics for each training problem.

  • A reference policy samples 16 trajectories per problem before each epoch to cache a reference accuracy and a mean token length, and the IDAC reward term then gives correct Think trajectories an efficiency bonus that decays exponentially with their length relative to that per-instance budget, scaled by how easy the problem is, while NoThink answers receive the full bonus.
  • Rewards are baselined by the reference accuracy and standardized across the mini-batch (BWS), which with AdaptThink-style importance sampling over a uniformly chosen mode token gives critic-free PPO-style training with no learned reward model or online reference queries, costing about 70 H100 GPU-hours for R1-Distill-Qwen-1.5B on the ~40k-problem DeepScaleR set.
  • On AIME24, Pass@3 rises from 46.0% to 56.0% while average tokens fall 27.9% (14,195 to 10,236), and on AIME25 it reaches 40.0% Pass@3 versus 32.0% for the base, whereas LC-R1 loses 10.0 points and AdaptThink 1.3 points on AIME24.
  • On MATH-500 the fraction of Think trajectories climbs from about 0.2 at Level 1 to over 0.7 at Level 5, with Level 1 tokens cut from 1,199 to 619 at 95.8% accuracy, and ablations attribute the accuracy gains to IDAC and BWS, with importance sampling mainly trimming easy-task tokens (GSM-Plus 1,652 to 1,052).
  • It is not the cheapest operating point, since several compression and routing baselines use far fewer tokens and DeepScaleR-Preview scores higher on AIME24 (58.0%) with fewer tokens, and the method requires verifiable rewards, depends on offline difficulty estimates that may be unreliable for ambiguous problems, and shows less pronounced gains on larger models.

DeepSeek-V4.1-Flash: Pushing the Limits of KV Cache Compression

Highlight HF pick · 23▲Large Language Models DeepSeek-AI, :, Anyi Xu, B. Li, Bangcai Lin, Bing Xue et al. Long-horizon agent workloads are input-heavy, so the compute cost of prefill and the size of key-value (KV) caches strain GPU high-bandwidth memory, SSD capacity, and data-transfer bandwidth. DeepSeek-V4.1-Flash is a multimodal Mixture-of-Experts (MoE) model with 552B backbone parameters and support for one-million-token contexts. Its Causal Encoder-Decoder (CED) architecture activates 16B parameters per token during decode but only 8B during prefill. Combining cross-layer KV cache reuse in Compressed Sparse Attention 2 (CSA2) with FP4 KV caching shrinks the cache that always stays in GPU memory to 890 bytes per token, about a quarter of DeepSeek-V4-Flash's footprint, while a deployment technique called SWA Bounded Replay cuts the persistent cache on SSD or host memory to roughly an eighth; the model was pretrained on 45T multimodal tokens, reportedly outperforms its predecessor on text and multimodal agentic tasks, and its checkpoints are publicly released.

Long-horizon agent workloads are input-heavy, so serving cost is now dominated by prefill compute and by KV cache pressure on HBM, SSD, and interconnect bandwidth. DeepSeek-V4.1-Flash is a 552B-parameter multimodal MoE with a 1M-token context that addresses this by splitting the network into a causal encoder and a decoder, sharing global KV across layers, and storing that KV in FP4.

  • The Causal Encoder-Decoder (CED) design splits the 40 layers into a 20-layer causal encoder and a 20-layer decoder whose global KV is projected from the final encoder hidden state, so prefill runs only the bottom half, activating 8B parameters per token versus 16B in decode and nearly halving prefill compute.
  • CSA2 statically assigns each layer a Full, Reindex, or Reuse mode to share main KV, indexer K, and Top-K indices across layers, and together with a QAT-trained FP4 main KV cache (E2M1 with one E4M3 scale per 16 channels) this brings the global KV footprint to 890 bytes per token, about 1/4 of DeepSeek-V4-Flash and 437x smaller than DeepSeek-V1.
  • SWA Bounded Replay approximately rebuilds sliding-window state by replaying only the last n_win tokens instead of L × n_win, which moves SWA KV off SSD into a short-TTL host-DRAM pool and cuts the persistent cache to roughly 1/8 of V4-Flash, while a Hierarchical Sparse Indexer restricts deeper decoder indexers to a fixed candidate pool (e.g. 16,384 positions) so single-token decode FLOPs grow only about 1/4 from 4K to 1M context.
  • The base model was pretrained on 45T multimodal tokens with sparse attention trained from scratch at 64K and is reported as comparable to DeepSeek-V4-Pro-Base at 1/3 the total and 1/4 the activated parameters with 5–10% gains on held-out evaluations, and the post-trained model, which uses a standard SFT, RL, and on-policy distillation recipe, is claimed to match closed frontier models on Terminal-Bench 2.1, DeepSWE v1.1, and AutomationBench.
  • The authors acknowledge a remaining gap to giant closed models on science-oriented agentic tasks such as Terminal-Bench 4.0 and on overall multimodal performance, and the bounded replay and Single-Pass mHC approximations rest on "negligible degradation" claims, with the extracted text (which is truncated) reporting benchmark results through figures rather than concrete scores.

Stress-testing Alignment Midtraining

Highlight Safety & Alignment Sid Baines, Jonathan Bostock, Maria Angelica Martinez, Andrew Draganov, David Africa, Daniel Tan Alignment midtraining (AMT) continues pretraining on large volumes of alignment-relevant documents so that desired behaviors generalize beyond the post-training data, but there is little public evidence that it works. The authors test its assumptions on models of up to 110 billion parameters with up to 1 billion midtraining tokens. They find that midtraining can steer a model's motivation when post-training data is ambiguous between two motivations, but a tiny fraction of finetuning data suggesting a competing motivation erases the effect. In rule-following scenarios, rules were learned robustly only when demonstrations appeared in either the midtraining or the post-training data, and the authors conclude that current public evidence does not show midtraining can address the core difficulties of aligning powerful AI systems.

Alignment midtraining (continued pretraining on alignment-relevant synthetic documents before post-training) is meant to make models generalise well where post-training data is ambiguous or incomplete. Controlled experiments on models up to 110B parameters and 1B midtraining tokens find that the effect is real under ideal conditions but brittle under small perturbations.

  • The pipeline midtrains gemma-3-12b, gemma-3-27b and GLM-4.5-Air on synthetic documents mixed 1:1 with Dolmino replay, instruction-tunes on Dolci-Instruct-SFT, then applies LoRA elicitation finetuning in a fictional Dispatch task where the model assigns trading crews by either following a seven-clause Charter or maximising profit (Coin).
  • With finetuning examples where both motivations give the same answer, midtrained GLM-4.5-Air follows its instilled motivation 90% (Charter) and 92% (Coin) of the time, but swapping just 164 of 8,192 examples (2%) for conflicting ones drops this to 13% and 46%, even though the models still describe and endorse the Charter equally in chat evaluations.
  • Generalisation to rules never demonstrated in finetuning is weak: Charter midtraining lifts held-out clause adherence only from 19% to 53% on GLM-4.5-Air and from 26% to 37% on gemma-3-27b, replacing worked demonstrations in the midtraining corpus with qualitative descriptions shrinks that uplift further (reported factors of 0.73 and 0.35), and in a separate fictional Python 4 setting held-out rule adoption actually decreases during finetuning.
  • Replacing supervised elicitation with GRPO-based RL on grafted Gemma-4-26B-A4B models cuts the midtraining uplift from 34% to about 8% in the no-thinking case, and reasoning traces show the model quoting Charter phrases verbatim before choosing the profit-maximising crew anyway.
  • The authors caution that most cells use a single seed, the settings are simple and synthetic, only three model families are covered, and their public-recipe midtraining may underperform whatever frontier labs actually use.

SoL-Pi: Recursively Scaling Auto-Research Loops for Efficient Agent Harness

Highlight HF pick · 31▲Agents Haozhe Liu, Tian Ye, Sensen Gao, Qihang Cao, Yitong Li, Mingchen Zhuge et al. Long unattended coding-agent runs make token efficiency of the agent harness a bottleneck. The authors run automated research loops over many diverse environments to discover harness improvements, keeping four mechanisms that survive selection, covering action execution, context compaction, observation handling, and delegated reading, which together form SoL-Pi. On the 51-task EdgeBench evaluation, SoL-Pi performs comparably to the Pi harness on GPT-5.6 Sol and Opus 5 while cutting recorded token traffic by 44.7-49.0% and API cost by about one third. Estimated hourly savings are $8.75-$13.50 relative to the native Codex and Claude Code harnesses and $4.36-$5.71 relative to Pi.

Long-running coding agents burn most of their budget on repeated context and redundant round trips, so this work points an AI "research agent" at the harness itself: it reads execution traces from a base Pi harness, proposes token-saving changes, and keeps only those that pass fixed capability and efficiency gates, with held-out results never fed back into search. Scaling this loop across roughly 150 proposed directions, 535 executable environments, and 3,000+ runs yields four surviving mechanisms that together form SoL-Pi.

  • The four mechanisms are Action Fusion (an edit plus its follow-up command in one tool request), Online Context Compact (compaction at plan-step boundaries only when projected savings beat the cache-rewrite cost), ObservationPack (outputs over 10 KiB are replaced by a handle and short excerpt after two requests, with exact retrieval on demand), and Evidence-Preserving Reducer (a cheaper model condenses build and test logs into a receipt that a deterministic verifier checks, falling back to the original on failure).
  • On the 51 public EdgeBench tasks with GPT-5.6 Sol, the full stack cuts token traffic by 49.0% and API cost by 33.2% ($894 vs. $1,339) while retaining 93.7% of Pi's score (42.0 vs. 44.8), and it costs 50.0% less than native Codex.
  • Applied unchanged to Opus 5, a backend never seen during search, it retains 94.3% of Pi's score with 44.7% less traffic and 33.5% lower cost, while single-mechanism variants actually raise scores by 5.3–12.8% (ObservationPack reaches 47.2 on GPT-5.6 Sol, Action Fusion reaches 50.5 on Opus 5).
  • Results elsewhere are more mixed: on 63 CPU-only Terminal-Bench 4 tasks SoL-Pi solves 15 vs. 18 for both Pi and Codex at 26.3% lower total cost, on Lean-verified IMO 2026 it matches Pi at 3 of 6 problems (versus 5 for Codex) with the lowest cost per pass at $20.90, and a 20-worker kernel-optimization swarm reaches 1,127 cycles at $60.11 versus 1,366 cycles at $82.12 for a Pi swarm.
  • The "comparable performance" claim hides a consistent 6% score drop for the full stack, 11 of the 51 EdgeBench tasks served as a one-way acceptance gate rather than purely held-out evaluation, mechanisms trigger less often on Opus 5 because search used only GPT-5.6 Sol trajectories, the swarm result is a single two-hour run per configuration, and the authors state their search counts establish no scaling law.

What Does Privileged Information Add to On-Policy Self-Distillation?

Highlight HF pick · 3▲Reasoning XiuYu Zhang, Wei Chow, Junfeng Fang, Zhenkai Liang, Tat-Seng Chua On-policy self-distillation (OPSD) trains a language model against a frozen copy of itself that is shown an answer or worked solution, and the question here is how much that privileged information adds beyond distillation alone. The authors build AMPLE-Math, 5,319 math problems each with six reasoning views sharing one answer, and compare every view against matched reference-free distillation. With a thinking-enabled teacher supervising direct-response rollouts, reference-free distillation accounts for much of Qwen3-1.7B's improvement, the extra benefit from references is modest, and complete traces add about two percentage points for SmolLM3-3B. Switching the student to long thinking-enabled rollouts turns the gains into losses in both model families, suggesting OPSD mainly improves access to existing reasoning ability through parameters shared across inference modes.

On-policy self-distillation (OPSD) trains a student on scores from a frozen copy of itself that sees an answer or worked solution, but it has been unclear how much that privileged reference adds beyond distillation itself. Holding the answer fixed across six reasoning views and comparing each against a matched reference-free control shows that most of the gain comes from cross-mode transfer, where a thinking-enabled teacher supervises direct-response rollouts. How much of the solution the reference reveals matters little.

  • AMPLE-Math pairs 5,319 problems from OpenThoughts-114k with six views sharing one verified answer, from Answer Only (13 tokens) to Full Trace (4,916 tokens), and Qwen3-1.7B and SmolLM3-3B are trained with LoRA for 100 steps against a control that drops the reference but keeps the thinking-enabled teacher.
  • In Qwen the reference-free student already gains +1.80 in-domain Avg@4 at step 100 and +4.07 pooled Avg@12 on AIME 2024/2025 and HMMT 2025 at step 50, a wrong-answer control gains +1.67 in domain, and gains concentrate on problems the base never solves directly but solves 62% of the time with thinking enabled.
  • The reference's own contribution is small and view-specific: Clean Solution adds 1.30 [0.20, 2.41] points over reference-free training in Qwen but does not survive Holm correction, Full Trace adds 2.0 points in SmolLM3 at step 50, and swapping in a length-matched reference from another problem costs about 2 points.
  • Replacing short direct-response training rollouts with long thinking-enabled ones turns gains into losses in both families with the references and evaluation unchanged; relaxing the loss at correction markers like "wait" barely changes their use, and a roughly four-point apparent gain from wider loss windows (First-4K, Distributed-1K) falls below one point once checkpoints are matched.
  • The evidence is limited to short-run LoRA training on mathematics in two small models, with seventeen single-seed interventions, all SmolLM3 configurations falling below the base by step 100, and a rollout comparison that changes reasoning mode, horizon, and supervised fraction together.

On-Demand Attention: Language Models Know When to Recall

Highlight Large Language Models Haibo Feng, Ruiqi Liang, Hanyang Peng, Shiqi Yu Full-attention decoding reads the entire growing history at every step even when it contributes little to the next token, which is costly for long-context reasoning and agentic workloads. On-Demand Attention (ODA) builds on the finding that a pretrained model's decoding states already predict how much a global read will help, and trains only a lightweight recall head that decides when to invoke global attention while otherwise decoding locally. Pretrained weights stay frozen and the full KV cache stays available for later recall, and a GPU-side conditional execution path in vLLM turns the skipped reads into real decoding speedups at long context. Across Qwen and Gemma models, including hybrid-attention backbones, selective recall recovers most of the performance lost under local attention while substantially reducing global reads.

Full-attention decoding reads the entire growing KV history at every step, even when distant context does nothing for the next token. ODA (On-Demand Attention) decodes with local attention first, then uses a small recall head, trained on the frozen model's own decoding states, to decide when a step is worth recomputing with global attention.

  • Each step runs a StreamingLLM-style Local pass (4 initial tokens plus a 2,048-token window), and a 28.3M-parameter recall head reads the previous hidden state, the current token embedding and the Local hidden state to predict the NLL gain of Full over Local minus a cost penalty; when the score exceeds a threshold, the step is recomputed with full attention over the completely retained KV cache, with the backbone weights never touched.
  • On Qwen3-1.7B, ODA scores 81.17 on RULER16K while calling Full on only 41.6% of steps (Full 81.94, Local 19.23) and 36.82 on LongBench v1 at 70.6% Full calls (Full 37.94, Local 23.66), with similar RULER16K recovery on Qwen3-8B (91.07 vs 92.59), the hybrid Qwen3.5-2B (94.08 vs 94.35) and Gemma-4-12B-it (95.27 vs 96.61).
  • Timing, not just budget, drives the result: random Full calls at a matched ~41% rate score 32.79 versus 88.96 for ODA on five RULER16K tasks, and on positions where Local's top-1 prediction is wrong the head predicts benefit better than Local entropy (AUROC 0.643 vs 0.486).
  • In a controlled vLLM run on one A100 with 128K input and a prescribed 12.5% recall schedule, ODA cuts major decoding FLOPs by about 76% and raises throughput from 75.54 to 149.52 tokens/s (1.98×), but it is 15.8% slower at 4K context, and that 12.5% rate is well below the 41–71% call rates the learned policy actually used in the quality evaluations.
  • Other limitations include LongBench results reported only for the 1.7B model, a separately trained head per backbone with no transfer test, a 10.33-point deficit on English passage retrieval, a train/deploy mismatch in how history states are built, batch-size-one timing only, and a full code release plus training GPU-hour accounting still pending.

Video DeltaNet: A Video-Native Hybrid Attention for Livestream Video Generation

Highlight HF pick · 3▲Vision Haocheng Xi, Yiming Xie, Hexu Zhao, Yiwen Zhang, Michael Liu, Thomas Creavin et al. Attention over long spatiotemporal token sequences is the main compute bottleneck in video diffusion models, and naive linear attention loses the fine-grained interactions needed for quality. Video DeltaNet (VDN) combines local softmax attention with a bidirectional linear memory whose Video Delta Attention updates once per frame using all of that frame's spatial tokens, with separate output projections, learnable gates, and a staged teacher-alignment recipe for retrofitting pretrained models. Instantiated on MiniMax H3 with eight-step distillation and an optimized SGLang serving stack, it denoises a 14.3-second 768p video in 6.70 seconds on eight NVIDIA B200 GPUs, a 14.5x speedup over the 50-step dense baseline.

Softmax attention accounts for more than 85% of denoiser runtime in long video diffusion, and replacing it outright with linear attention degrades generation quality. Video DeltaNet (VDN) keeps exact Softmax only within a local temporal window and for first- and last-frame anchors. The remaining long-range context goes to a bidirectional linear memory that is updated once per frame with a new delta rule, and the design is retrofitted onto pretrained MiniMax H3 rather than trained from scratch.

  • Each query chunk attends with Softmax to a 15-frame window aligned to the VAE's five-frame chunks, plus the first and last latent frames; forward and reverse linear scans, each initialised with half of a text-summary state, cover everything outside the window, and the two branches are merged through separate gates, RMS normalisation and output projections.
  • Video Delta Attention defines each frame's state as the solution of a joint regularised least-squares problem over all of the frame's spatial tokens, giving the closed form S_t = (S̄_t + B_t)(I + A_t)^-1 with the inverse computed in the small key-channel space; this couples writes from overlapping keys and gives a provably non-expansive inherited-state transition without the 1/√U key scaling that SANA-WM needs.
  • With the backbone frozen throughout, adaptation runs 200 steps of per-layer alignment, 500 steps of end-to-end alignment and 2,000 steps of rank-64 LoRA co-adaptation on 10,015 clips; a DMD2-style distillation without the GAN term then trains the eight-step sampler for 250 generator steps.
  • The optimised backbone is 2.6× faster per evaluation on one B200 and 3.2× faster on one H200, with Softmax attention density falling from 42.1% to 20.0% as clips grow from 42 to 102 latent frames; eight-step VDN-H3 on eight B200s denoises a 14.3-second 768p video in 6.70 seconds, 14.5× faster than 50-step dense H3 on the same GPU count.
  • On 103 third-party prompts, eight-step VDN-H3 matches or slightly exceeds 50-step dense H3 on five no-reference quality metrics (+0.06 to +1.00), while four-step FastH3 falls 2.70–12.74 points below dense H3; however, World Coherence (1.77 vs 1.84) and endpoint LPIPS (0.1156 vs 0.1044) are slightly worse, the evaluation uses automatic metrics on a single base model, the latency figure covers DiT denoising only, and the ablations are kernel-level, so VDA's quality contribution over a batched delta rule is not isolated.

RetireOPD: Self-Retiring On-Policy Distillation for Agentic Reinforcement Learning

Highlight HF pick · 7▲Reinforcement Learning Yan Yu, Zhengxi Lu, Yizhou Liu, Yichen Pan, Aozhe Wang, Qipeng Chen et al. Multi-turn agents trained with reinforcement learning (RL) get only one scalar reward per trajectory, and on-policy distillation (OPD) from a skill-conditioned self-teacher is meant to add dense token-level supervision, but the authors find that privileged information does not always make the teacher reliable and that its benefit depends on the training stage. RetireOPD first optimizes a decoupled, skill-conditioned teacher with environment rewards, then trains a skill-free student jointly with RL and OPD. With Adaptive Retirement, the student drops the teacher once their discrepancy stops shrinking and it reaches a target fraction of the teacher's success rate, after which training continues with RL alone. Across Qwen2.5 models from 1.5B to 7B, it improves ALFWorld success rate over the RL baseline by 14.1% to 18.8% and WebShop accuracy by 11.8% to 19.0%, surpassing its own teacher in every setting.

Multi-turn agents trained with RL get a single scalar reward per trajectory, so recent work adds dense token-level supervision by distilling from the same model prompted with privileged task skills. The authors show that such a teacher is often no better than its student, and that its guidance turns from helpful to restrictive partway through training. RetireOPD first trains a separate skill-conditioned teacher with environment rewards. It then trains a skill-free student with GRPO plus on-policy distillation and drops the teacher online once it stops helping.

  • Teacher and student start from the same base model: the teacher is trained with GRPO while seeing skills retrieved from the SkillRL SkillBank and is then frozen, and the student learns on its own rollouts with GRPO plus a reverse-KL distillation term (weight 0.01) estimated from the teacher–student log-probability gap on sampled tokens.
  • Every 5 steps the method checks two signals and retires the teacher at the first window where the teacher–student gap has stopped shrinking and the student's success rate, averaged over two windows, reaches 90% of the teacher's, after which training continues with GRPO alone and needs no further teacher forward passes.
  • Across Qwen2.5 1.5B/3B/7B, ALFWorld success reaches 89.8 / 93.8 / 95.3% versus 72.8 / 75.0 / 81.2% for GRPO (+14.1 to +18.8 points) and WebShop accuracy reaches 75.8 / 77.3 / 84.4% versus 56.8 / 63.3 / 72.6% (+11.8 to +19.0 points), also beating GiGPO and the method's own skill-conditioned teacher in every setting (3B ALFWorld: 93.8% vs 79.7%).
  • Ablations on ALFWorld back both design choices: skill-prompted teachers without reward training reach only 28.9% (3B) and 23.4% (7B) versus 79.7% and 90.6% after training, keeping distillation for all 150 steps yields 82.8% against 92.2% with retirement, either retirement signal alone yields 89.0%, and varying the thresholds moves the retirement step between 55 and 95 while success stays within 89.1–92.2%.
  • Evidence is limited to two benchmarks and models up to 7B, the separately RL-trained teacher adds a training run whose cost is not quantified, margins over always-on GRPO+OPD are as small as 2.3 points on a 128-episode validation set with no seed variance shown, and the full method's 3B ALFWorld score appears as 92.2% in the ablations but 93.8% in the main table without explanation.

JEPA-Anything: Learning Predictive Models across Different Worlds

Highlight HF pick · 21▲Other Taoyong Cui, Zhongyao Wang, Xinyue Xu, Weiyang Liu, Zhaochen Yu, Yuying Zhang et al. Predictive world models are typically built per domain, and the question here is whether one learning principle can serve very different systems. JEPA-Anything extends joint-embedding predictive architectures with orthogonal predictive factorization (OPF), which decomposes latent targets into complementary factors, learns them through dedicated pathways, and recombines them in a shared predictive design. It is evaluated across seven domains: vision, biology, clinical trajectories, control, molecular dynamics, physical fields, and weather. Against matched JEPA baselines it improves reported metrics on all 10 dynamics tasks, cuts single-intervention prediction error on Interventional Pong by 34.8%, and achieves the lowest one-step and 100-step molecular errors in all four systems; the authors also report experimental support for a factor-nominated biological intervention and latent orbital modes that recover the Keplerian scaling exponent.

Predictive world models are usually built per domain, and standard JEPA packs every predictable mode of a system into one monolithic target embedding, so easy or high-variance structure can crowd out weaker signals. JEPA-Anything adds orthogonal predictive factorization (OPF), which splits the latent target into orthogonal subspaces with dedicated predictors and recombines them into a full latent state. The same core is tested across seven domains, from vision and single cells to molecules and weather.

  • OPF projects the stop-gradient EMA target through K learned projectors (typically K=4, with K·r = d), regresses each factor with its own predictor head, enforces within- and cross-factor orthogonality plus activity floors on the factors and the online encoder, and synthesizes the next state via a pseudoinverse, all as an additive loss on top of each domain's existing objective.
  • Against matched monolithic JEPA baselines it improves reported metrics on all 10 dynamics tasks (CausalWorld, DMC, PDEBench, WeatherBench2), cuts single-intervention MSE on CITRIS Interventional Pong by 34.8% (12.9% on unseen intervention combinations, 8.6% on six-step rollout), and lowers APEBench Burgers error by about 49.5% on held-out late states and 44.7% over six rollout steps.
  • It achieves the lowest one-step MAE and 100-step RMSD on all four molecular systems compared with TrajCast-JEPA (paracetamol RMSD 1.868 to 1.776 Å), and beats Cell-JEPA on single-cell tasks (PBMC zero-shot AvgBIO 0.775 vs 0.719, Norman Pearson 0.814 vs 0.787).
  • A mechanism audit shows the orthogonality constraint is what makes state synthesis stable, with a condition number of ~1.0 vs 438.5 and cross-factor overlap of ~1e-16 vs 0.455 for a capacity-matched unconstrained multi-head; separately, factor coordinates nominated an IL-18 plus CD73-blockade combination that was supported in co-cultures, organoids, tumor fragments, and mice, and recovered the Keplerian exponent with a fitted slope of −1.4991.
  • Several gains are thin or mixed: visual binding moves INJ only from .572 to .581 on DINOv3, DMC pixel dynamics is nearly flat, the 50-step Burgers advantage shrinks to about 3%, Hopper planning favors standard JEPA, the orbital analysis rests on a single run, and each domain still trains its own encoder and adapter, so this is a shared training recipe and not one cross-domain model.

An Empirical Study of Harness Design for Coding Agents

Highlight HF pick · 30▲Agents Run-Ze Fan, Zihao Zhang, Simin Ma, Yebowen Hu, Shouju Wang, Kaiqiang Song et al. Coding-agent harnesses are usually evaluated as monolithic systems, so the contribution of individual components is unclear. Using a lightweight harness with a fixed execution loop, the authors vary planning, action space, and context management across four models on SWE-Bench Verified and Terminal-Bench 2.1, covering 176 matched settings. Context management matters more as the context-window budget tightens, mostly by preventing overflow failures, and staging rule-based elision before LLM-based summarization is the most efficient strategy, while making elided content recoverable yields no accuracy gain. Planning shifts from an accuracy scaffold for weaker models to a cost saver for stronger ones, and bash-capable models work well with a bash-only interface at substantially lower cost, whereas predefined tools help models with weaker bash proficiency.

Coding-agent harnesses are usually benchmarked as monolithic systems, so it is unclear whether a gain comes from planning, tool design, or context management. This study fixes a lightweight ReAct execution loop and varies those three components independently across 176 matched settings, covering Nemotron-3 at 30B, 120B and 550B plus Mistral-Medium-3.5-128B on SWE-Bench Verified and Terminal-Bench 2.1.

  • Five context-management tiers are swept across 32k, 64k, 96k and 128k window budgets: T0 (none), T1 (rule-based elision of stale tool outputs), T2 (elision plus a recall_event retrieval tool), T3 (LLM summarization) and T4 (elision at 60% of the window, then summarization at 85%). Planning via an update_plan tool and a bash-only action space are ablated at T4/128k, and success rates are compared with paired McNemar tests under Benjamini–Hochberg correction.
  • Context management pays off mainly by preventing overflow failures: the model-averaged gap between the managed tiers and T0 on SWE-Bench Verified shrinks from 35.7 points at 32k to 2.7 at 128k. Over the same range the T0 overflow rate falls from 78.7% to 8.7%, and no managed tier ever overflows.
  • T4 matches the accuracy of the other managed tiers at the lowest mean cost at every budget, because cheap early elision avoids many summarization calls. Recoverable elision adds nothing: 56.3% of recall-enabled settings never call recall_event, and T2 trails T1 by 0.36 points on average.
  • Planning acts as an accuracy scaffold for Nemotron-3 30B, adding 11.6 points on SWE-Bench Verified by keeping runs alive long enough to attempt an edit. For Nemotron-3 550B and Mistral-Medium-3.5-128B it instead cuts SWE-Bench cost by roughly 30% and 32%, with 2.0- and 0.4-point accuracy drops, by trimming redundant post-edit verification.
  • Predefined tools lift Nemotron-3 30B by 15.0 and 10.1 points on the two benchmarks, while bash-only gains Nemotron-3 550B 3.6 and 5.6 points and cuts its cost by 53% and 30%. Mistral-Medium-3.5-128B splits by task type: bash-only costs it 23.2 points on SWE-Bench Verified but gains it 6.7 on the shell-centric Terminal-Bench 2.1.
  • Several limits apply: planning and action space were tested only at T4/128k, and each setting was run once per task. With only 89 tasks, many Terminal-Bench 2.1 contrasts miss significance. The bash-only ablation also bundles tool availability with prompts, file-state tracking and post-edit diagnostics, and the crossover points come from four open models and a Python-only SWE-Bench Verified.

Applications 117

CovR: Coverage-Aware Hardware Verification via Reasoning-Guided Reinforcement Learning

Manar Abdelatty, Maryam Nouh, Sherief Reda cross-listed Hardware design verification can consume up to 70% of development effort, and existing large language model (LLM) testbench generators focus on functional correctness while neglecting coverage. CovR is an agentic framework that combines self-reflection loops with simulation feedback, used to build a dataset of 16,514 specification, RTL, reasoning, and testbench tuples. A student model is then trained with reinforcement learning (RL) using rewards from simulation and coverage tools. The fine-tuned model reaches 93.81% cov@10 on VerilogEval and RTLLM V2.0 and 87.76% on CVDP, beating prior state of the art by 7.97% and 3.59%; placed back in the agentic loop it rises to 94.27% and 91.39%, and as a stimulus engine in full verification workflows it improves coverage by 18.95%.

Robust Conformal Intrusion Detection via Traffic-Aware Calibration and Attack-Orbit Invariance

Zhenpeng Li cross-listed Large language models fine-tuned for network intrusion detection give single predictions with no statistical guarantees. Conformal prediction adds a coverage guarantee, but thresholds calibrated on clean traffic fail once an attacker perturbs network features they control, as the authors show on three benchmarks. Their traffic-aware conformal prediction calibrates on traffic generated by the attack the defender expects, and provably restores coverage when that attack can be sampled. Against a stronger attacker who queries the model's scores, they remove attacker-controllable features and anything derived from them from the model's input. This yields an exact, pathwise coverage guarantee that held under every evaluated attack, at a cost of 7 to 14 points of clean accuracy.

AURORA: A Natural Language-Driven Agentic Framework for Understanding, Reasoning, and Orchestrating Reliable Air-Ground Co-Simulation

Keshu Wu, Hao Zhang, Rui Gan, Xiangbo Gao, Xiaopeng Li, Zhengzhong Tu et al. cross-listed Building co-simulation scenarios for combined air and ground transportation is labor-intensive, and a generated scenario can run without errors while failing to realize the spatial, temporal, communication, or behavioral relationships the user asked for. AURORA treats generating scenarios from natural language as compilation with verification. Its core is a typed intermediate representation, the Air-Ground Scenario Graph (AGSG), which supports feasibility checks before execution, runtime verification against traces, failure localization, and bounded repair. On the new AURORA-Bench, which scores whether scenarios actually realize the requested interactions rather than merely execute, runtime verification exposes silent failures that completion-based evaluation misses, and localized repair fixes many of them without regenerating the whole scenario.

The Output-Space Hypothesis: Enumerative Equivalence Checking for Tensor Programs

Paul Biberstein, Joseph Devietti, Mayur Naik cross-listed Optimized tensor programs such as GPU kernels are usually judged correct when differential testing on random inputs finds no mismatch, which misses bugs that appear only for rare inputs with precise relationships between values. Dirigo flips the check: instead of testing every output location for one input, it uses a new symbolic execution strategy to verify a single output location for all possible inputs. On a public dataset of 6,988 AI-written CUDA kernels, all marked correct by differential testing, it found 600 buggy kernels, and it caught 97.3% of those bugs within two minutes.

TorchCraft: Unified binder design by inverting an all-atom structure predictor

TorchCraft Team, Yu Liu, Zhouhanyu Shen, Zhengyi Li, Xikun Huang, Jiaqi Liu et al. All-atom structure predictors capture rich priors about molecular interactions, but reusing them to design binding proteins is difficult. TorchCraft, implemented in TorchFold, optimizes sequence logits through a frozen all-atom predictor. It combines confidence, contact, geometric, and sequence-prior objectives in one procedure that covers minibinders, framework-conditioned VHHs, cyclic peptides, and ligand-binding proteins. Using pretrained AlphaFold 3 weights and no post hoc sequence redesign, it produced minibinders and VHHs with experimentally measured binding across four targets in each format, and computational benchmarks support its use for cyclic peptides and ligand-conditioned pocket design.

Trust, but Validate the Instrument: Auditing AI-Generated RTL Verification Plans on Authored Security-Regression Proxies

Hang Xiao, Chuhong Xu, Kainan Zhou, Gangzhen Qian, Lu Yi cross-listed Large language models can produce hardware verification plans that conform to a provider's response schema yet still fail when run through a trusted execution pipeline. The authors build SecTB-RTL, an auditable benchmark of 31 tasks and 124 authored hardware-security regressions, on which a deterministic non-AI baseline killed up to 78 mutants. In a preregistered run of 1,860 model calls, the provider accepted 1,857 responses but only nine passed the production semantic validator, because the generation rules and the execution rules did not match. The authors therefore treat the run as an instrument-validation incident rather than estimating any prompt effect, and argue that schema acceptance, compilation, and coverage do not show that an output will execute correctly.

AURA: Adaptive Uncertainty-Routed Analysis for Email Threat Detection

Omran Berjawi, Walid fahs, Rida Khatoun Spam and phishing detectors struggle to generalize as attackers use large language models to write convincing malicious emails. AURA (Adaptive Uncertainty-Routed Analysis) first runs a URL classifier and measures how uncertain its prediction is, and sends only ambiguous messages to a fine-tuned transformer encoder that analyzes the email's content. Trained on eight heterogeneous corpora, it reaches a macro F1 of 0.9858 in-distribution and holds 0.9502 and 0.9436 on the held-out real-world corpora NazPhish-Eval and GuenterTrap-Eval, which span a decade of attack campaigns.

Delphi Scanner: efficient and interpretable static malware detection via API sequence modeling

Bijied Brahimi, Vincent Cohadon, Gabriel Glazman, Rayan Al Mohaize, Omran Berjawi, Rida Khatoun cross-listed Static malware detection for Windows Portable Executable (PE) files has to balance detection accuracy, compute cost, and interpretability. Delphi Scanner classifies files with a convolutional neural network (CNN) over Windows API call sequences. A separate rule-based layer maps the APIs to high-level malicious capabilities so analysts can interpret the result. On over 190,000 PE files it reaches 95.35% accuracy with a 1.53 MB model. Robustness tests on 5,647 out-of-distribution MalwareBazaar samples, on paired packed and unpacked executables, and against three adversarial evasion strategies suggest it generalizes beyond its training distribution.

Digital Twins for Opinion Dynamics: A Generative LLM Framework for Social Networks

Omran Berjawi, Giuseppe Fenza, Rida Khatoun, Sherali Zeadally Research on opinion dynamics relies either on simplified mathematical models that ignore language and context, or on LLM simulations that have not been checked against real data. This framework builds a digital twin by cloning a real Twitter network and giving each agent attributes such as persona, emotions, centrality, stubbornness, and influence. Mistral-7B then updates each agent's opinion based on its memory and what it sees from others. Tested against COVID-19 and 2020 U.S. election Twitter datasets, it cuts individual prediction error by more than 50% versus the best classical baseline, with mean absolute error of 0.150 and 0.121. It also better matches network structure and polarization dynamics, and ablations show that agent attributes contribute most to accuracy.

Robust Workflow Generation via Adversarial Learning for Audio Deepfake Detection

Xiang Li, Pin-Yu Chen, Wenqi Wei cross-listed Audio deepfake detectors that perform well under controlled conditions often fail under real-world perturbations and corruptions. ROGUE treats detection as building a workflow step by step, orchestrating multiple detection tools, and trains it with two adversarial agents: a perturbation agent that corrupts the audio and a policy agent that learns which detection tools to select and how to execute them under those perturbations. The adversarial training produces perturbation-aware tool selection and adaptive execution. Across multiple datasets and real-world corruptions, ROGUE consistently outperforms strong baselines in robustness and generalization.

Perception, Layout, and Validation: Calibrated Confidence for Reliable Straight-Through Processing of Financial Documents

Yichao Jin, Yushuo Wang, Yuxuan Han, Kwan Ching Yee Sonia, Weiyang Song, Chiu Jin-Chun Kent et al. Straight-through processing (STP) of financial documents means auto-approving extracted key-value fields without human review, which requires calibrated confidence and a bounded error rate on the approved fields. The verbalized confidence of vision language models (VLMs), however, tracks correctness poorly. The authors break confidence down into three interpretable channels, perception, layout, and validation, and apply conformal risk control on top, testing on real invoices, synthetic invoices, and ad-buy forms with Qwen3.6-27B and Gemini-3.1-Flash-Lite; the decomposed score raises AUROC from 0.54-0.74 to 0.90-0.99. At a target error below 10%, it auto-approves 49-72% of fields versus only 0.1-7.0% with native VLM confidence, while keeping the empirical error of accepted fields at or below target.

How Far Can Sub-3B Open Language Models Go in Zero-Shot Essay Scoring on an 8 GB Consumer GPU?

Nguyen Dung Son, Dang Quang Minh, Nguyen Huu Loi, Truong Viet Vu, Nguyen Thai Anh Automated essay scoring is most needed in places like public schools, where privacy rules often forbid sending student writing to third-party APIs. The authors therefore test how well open models under 3B parameters, running locally on a single 8 GB consumer GPU, can score essays zero-shot. Evaluating Qwen2.5 at 0.5B, 1.5B and 3B and SmolLM2 at 1.7B on all eight ASAP-AES prompts, they find that scoring each rubric trait separately beats holistic prompting. Min-max normalization from Multi-Trait Specialization rescues a poorly calibrated model (macro QWK rises from 0.204 to 0.388), but the best local configuration (0.388) remains well below both human agreement (0.769) and a length-only baseline (0.523), so the authors recommend these models only for formative feedback under human supervision.

Cross-Architecture Foundation-Model Distillation for Edge Flood Segmentation

Fabian Schmalstieg, Karsten Mueller, Wojciech Samek cross-listed Geospatial foundation models segment floods well but are too large for memory-constrained edge hardware. The authors distill a 300-million-parameter Prithvi-EO-2.0 teacher, fine-tuned on 252 labeled Sen1Floods11 scenes, into a 0.7-million-parameter EfficientViT-B0 student, using the teacher to label extra unlabeled Sentinel-2 imagery. With 2,500 teacher-labeled scenes, the student reaches 0.787 water intersection over union against the teacher's 0.822, matches the teacher on STURM-Flood, and stays below it on WorldFloods-v2. After quantization-aware training, the student runs as a 1.5-megabyte 8-bit integer TensorRT engine on a Jetson Xavier NX at 5.57 milliseconds of graphics processing unit (GPU) compute per 512-by-512 image, although a fixed modified normalized difference water index (MNDWI) threshold is competitive with both models on the two clean external benchmarks.

greCAPTCHA: Assessing Understanding as Evidence of Research Authorship Under Generative AI

Justin Payan, B\'alint Gyevn\'ar, Atoosa Kasirzadeh, Nihar B. Shah cross-listed Institutions reviewing manuscripts can no longer assume that named authors exercised real oversight over potentially AI-generated work. greCAPTCHA is a proctored assessment that generates questions at multiple levels of understanding about a manuscript and scores authors on their "capacity to verify," meaning the knowledge and reasoning needed to critically assess their own contributions. In a user study with 31 researchers, its automated scores distinguished papers participants had authored from ones they had not with an AUC of 0.90. Participants judged the construct appropriate for measuring author understanding but suggested important changes before deployment.

SAFARI: An Industrial Benchmark for LLM-Assisted Hazard Analysis and Risk Assessment

Chenxi Wu, Zimu Wang, Haiyang Zhang, Wei Wang, Zhijie Xu Large language models are being considered for safety-critical engineering, but their reliability in regulated functional-safety workflows is poorly measured. SAFARI is a benchmark of 3,000 de-identified industrial automotive Hazard Analysis and Risk Assessment (HARA) cases under ISO 26262, covering open-ended hazard analysis and standards-grounded risk classification, with a reference-anchored LLM-as-a-judge protocol that correlates well with experts. Across nine frontier models, hazard narratives are often plausible but risk classification is weak, with the best Automotive Safety Integrity Level macro-F1 reaching only 0.261, and chain-of-thought prompting frequently makes categorical assessment worse. Error analysis traces failures to omitted scenario-critical context during hazard generation and to misjudged controllability during risk assessment.

Q&A on Any Spreadsheet Requires Interpreting Its Grid Structure

Zofia Smole\'n Question answering over spreadsheets with retrieval-augmented generation (RAG) depends on how a two-dimensional grid is split into chunks an LLM can interpret. A framework that chunks any spreadsheet using semantic cell role annotation beats prior state of the art, with the benefit coming from richer context for answer generation rather than better retrieval accuracy. The authors argue the approach hits a hard ceiling because finite, pre-defined cell classes cannot capture the open-ended structure of spreadsheets, even with human-level annotation, and call for dimensionality-reduction methods that flatten 2D spreadsheets directly into 1D text.

Large Language Models as Falsifiers for Cyber-Physical Systems

Ali ArjomandBigdeli, Jiawei Zhou, Stanley Bak cross-listed Falsification looks for inputs that make a cyber-physical system violate a formal specification, typically by minimizing the robustness degree of a Signal Temporal Logic (STL) formula with black-box optimizers. LLM-Falsifier uses a large language model as the iterative optimizer and feeds it semantic information that numerical optimizers lack, including natural-language input and output names, output trajectories, and the critical time points that determine the minimum robustness value. On the ARCH-COMP falsification benchmarks it needs fewer simulations on average to find a counterexample than existing tools on 14 of 21 specifications, including surrogate-based, Bayesian, and search-based methods.
100 more specialized papers

Other 50

Radio-Frequency Convolutional Neural Networks

Zhihui Gao, Shi-Yuan Ma, Yiran Chen, Dirk Englund, Tingjun Chen Edge devices such as phones, wearables, and drones rarely have enough compute for modern neural networks, and adding accelerators increases size, weight, power, and cost. Radio-frequency convolutional neural networks (RF-CNN) reuse the frequency mixer already in every wireless radio, which naturally performs convolution in the frequency domain, by mapping multi-channel convolutions onto frequency tones that a passive mixer computes in one pass. Hardware experiments run CNNs of up to 26.4 million parameters and nine layers, for signal and image classification and controllable image generation, with results close to full precision. Since the weights arrive over the air and the analog hardware is shared with communication, the device spends energy only on preparing inputs and reading outputs, as low as 0.72 femtojoules per multiply-accumulate, about 100 times less than an added digital processor.

Search at the Cost of Sampling: Nearly-Instant Latent Space Bayesian Optimization

Donney Fan, Colin Doumont, Aleksandra Kalisz, Paul Duckworth, Jacob R. Gardner, Henry Moss et al. Bayesian optimization (BO) is a natural fit for generative de novo design pipelines, but its per-step overhead becomes the bottleneck when virtual screens are cheap. The authors pair a linear surrogate model with the spherical domain where high-dimensional latent vectors concentrate, and exploit spherical symmetry to derive nearly closed-form solutions for both surrogate fitting and acquisition. The result is at least a 100x speedup over state-of-the-art baselines with matching or better performance on molecular and image generation benchmarks, making BO a practical drop-in where it was previously too slow.

Efficiently Linking Unstructured Data for Multi-step Reasoning

Jiaming Liang, Haydn Jones, Jacob R. Gardner, Mark Yatskar, Zachary Ives cross-listed Data-engineering workflows built on LLMs and agents often begin by retrieving evidence from unstructured sources. That retrieval combines multi-attribute filtering, multi-vector search, exact relational joins, and thresholded embedding-similarity joins. The DASE query engine runs these jointly, using SemJI, a sparse materialized index of rare near-neighbor pairs, and an execution layer with predicate-aware approximate nearest-neighbor traversal, batched access, and threshold-based score aggregation. On scientific-discovery workloads it retrieves candidate evidence 6x to 46x faster than relational database, reranking, and vector-database baselines at comparable recall. As a prefilter on SemBench E-Commerce, it raised BigQuery quality from 0.67 to 0.80 and cut cost from $2.42 to $0.54.

Conservation Buys Stability and Factoring Buys Counterfactuals in Physical World Models

Yufeng Wang, Parivesh Priye, Lu Wei, Haibin Ling Learned physics simulators fail in two distinct ways: they drift into implausible behavior over long rollouts, and they keep following the training-time law after a physical parameter is intervened on. The authors argue each failure needs a different structural fix. Evolving a learned energy with a symplectic integrator keeps rollouts bounded and physically meaningful for up to 100 times the training horizon, where equal-capacity predictors, an energy-regularized model, and a tuned neural ordinary differential equation diverge. Encoding the physical coupling through an explicit linear factorization instead lets a model follow a never-seen sign of that coupling. Matched ablations show a double dissociation: removing the stability structure leaves counterfactual transfer intact, while removing the factorized coupling destroys counterfactual transfer without eliminating stability, and this holds beyond the three-body system and when the state must be inferred from pixels.

Design of the IBM Granite 5.0 TurboCTC ASR Model

Brian Kingsbury, George Saon, Masayuki Suzuki, Hong-Kwang J. Kuo, Takashi Fukuda, Samuel Thomas et al. IBM describes Granite 5.0 Turbo CTC, a 470-million-parameter encoder-only automatic speech recognition (ASR) model designed for a strong speed-accuracy tradeoff. The architecture adds pyramidal temporal subsampling inside Conformer blocks via strided depthwise convolutions, block-diagonal chunk-wise self-attention, and conditioning on intermediate predictions from the middle layer. The model is trained only on public data using the Muon optimizer and balanced data sampling. Inference optimizations, such as replacing 1x1 convolutions with linear layers and speeding up attention, place it on the speed-accuracy Pareto frontier of the Open ASR Leaderboard for English short-form ASR while being twice as fast as the fastest competitor, and it is released under a permissive license.

Designing Against Deskilling: Metacognitive Feedback Reduces Cognitive Offloading to LLM Assistants

Sebastian Maier, Kai Schwabe, Manuel Schneider, Stefan Feuerriegel cross-listed Cognitive offloading to AI assistants can erode skills by removing chances to practice, and it is unclear how to prevent this without restricting access to AI. In a preregistered online experiment (N = 704) with a 2x2 design plus a no-AI control, participants practiced fraction arithmetic with an LLM assistant that gave solutions only on explicit request, then took an unaided test. Metacognitive feedback that spelled out what offloading means for the learner cut the odds of offloading answers roughly in half (odds ratio 0.47) and improved test performance (odds ratio 1.51). An effort-based reward for using less assistance had no detectable effect on either outcome.

When Does Retrieval Help Time-Series Forecasting?

Mert Onur Cakiroglu, Elham Buxton, Mehmet Dalkilic, Hasan Kurban Published retrieval plug-ins for deep time-series forecasters each report consistent gains and credit their own mechanism. The authors argue that the benefit depends instead on the relation between the lookback window length and the data's dominant seasonal period, which standard evaluation protocols never vary. With a 12-step window, a simple control that repeats the last observed period beats six standard backbones on four of seven benchmarks by 8% to 44% in MSE, though it loses by up to 25% on datasets without a strong shared period, and a zero-shot foundation model trails trained backbones by 22% to 50% on the periodic benchmarks. Exact lookup performs as well as graph diffusion, and two interpretable statistics, a trend test and a staleness rate, predict whether retrieval will help with 0.76 accuracy under leave-one-dataset-out evaluation.

COMPASS: Ordered Clustered Routing at 100K Scale

Ido Greenberg, Hugo Linsenmaier, Piotr Sielski, Shie Mannor, Alex Fender, Gal Chechik et al. Many large routing problems require visiting clusters of nodes in a prescribed order, known as the Ordered Clustered Traveling Salesman Problem (OCTSP), and optimizing each cluster independently misses dependencies across clusters. COMPASS combines search with learning-accelerated routing by orchestrating parallel sub-solvers. Its solutions keep improving with more compute, and it can reach exact solutions in time exponential in cluster size rather than instance size. It accepts general distance matrices rather than only coordinates, consistently outperforms alternatives, and scales to 100K synthetic nodes and 28.5K real e-commerce nodes, the latter being the largest reported routing solution over asymmetric distances, 9× beyond established benchmarks.

RISC-V and machine learning: a survey

Shriman Keshri, Apparna Singh, Chinmaya Kumar Palo, Shreya Adya, Subhankar Mishra A survey of the RISC-V instruction set architecture in machine learning covers academic and commercial implementations, instruction set extensions, core designs, compiler optimizations, software frameworks, and deployment strategies. It contributes a unified taxonomy of RISC-V machine learning implementations, a comparison of performance and design trade-offs, and an assessment of software toolchain maturity. The findings point to progress in energy efficiency, specialized instructions, and framework integration alongside persistent problems with standardization, verification complexity, and ecosystem fragmentation. Four research directions are proposed: specialized neural processing extensions, adaptive and modular processor architectures, security frameworks, and energy-efficient multi-domain architectures.

Prediction-Powered Smoothing and Validation for Disaggregated AI Evaluation

Sho Kawano, Zehang Richard Li, Paul A. Parker cross-listed Reporting AI system performance separately per domain, such as task type or conversation type, is unreliable when few labeled examples exist per domain, and direct estimators including prediction-powered inference (PPI) use only a domain's own labels. Borrowing from small area estimation, PP-S fits a Bayesian smoothing model to each domain's prediction-powered estimate, PP-TS extends it to share strength across a reporting taxonomy, and a new approximately unbiased design-based cross-validation score chooses between direct and smoothed estimators. On a curated benchmark with verifiable grading and on human-graded deployed agent traffic, the smoothed estimators improve point and interval estimates with near-nominal coverage, and the score selects as well as an independent validation sample at the same budget.

JEPA-Anything: Learning Predictive Models across Different Worlds

Taoyong Cui, Zhongyao Wang, Xinyue Xu, Weiyang Liu, Zhaochen Yu, Yuying Zhang et al. Predictive world models are typically built per domain, and the question here is whether one learning principle can serve very different systems. JEPA-Anything extends joint-embedding predictive architectures with orthogonal predictive factorization (OPF), which decomposes latent targets into complementary factors, learns them through dedicated pathways, and recombines them in a shared predictive design. It is evaluated across seven domains: vision, biology, clinical trajectories, control, molecular dynamics, physical fields, and weather. Against matched JEPA baselines it improves reported metrics on all 10 dynamics tasks, cuts single-intervention prediction error on Interventional Pong by 34.8%, and achieves the lowest one-step and 100-step molecular errors in all four systems; the authors also report experimental support for a factor-nominated biological intervention and latent orbital modes that recover the Keplerian scaling exponent.
39 more specialized papers

Agents 48

Message capacity and claim wording set the transition points of collective truth-finding in language-model networks

Makoto Fukushima cross-listed Groups of large language model (LLM) agents can converge on a wrong consensus even when most start out correct, and this work asks how much of that outcome is set by message capacity, the number of peers' messages each agent reads. Across 31,824 randomized queries, an 8-billion-parameter model's judgment of a claim reduced to a logistic function of a weighted sum of its inbox. Yet predictions built from these weights and the network structure failed: the correct side won in only 28-45% of episodes even when 75% of agents started correct. The failure traced to a threshold that the claim's wording sets before any message is read, which follows what a claim asserts rather than whether it is true; with each claim's own threshold the same weights reproduce the outcomes, the predicted transition points held on a second 8B model, and the assertion bias was not detected at 70B.

Position: It is Time to Virtualize Foundation Models with a Self-evolving Operating System Layer

Suparna Bhattacharya, Tarun Kumar, Cong Xu, Satish Kumar Mopur, Jiahao Li, Ashish Mishra et al. Compound agentic AI stacks are fragmented. Protocols such as MCP and A2A ease connections between tools and agents, but each framework still builds in its own runtime for state, memory, budgets, and guardrails, so behavior does not carry over between frameworks and governance breaks easily. The authors compare this to computing before operating systems and call for a Foundation Model Operating System (FMOS). This layer would virtualize foundation model interactions the way virtual machines abstract hardware, giving applications the illusion of dedicated, trustworthy model instances with effectively unbounded capabilities. Internally, it would manage memory tiers, model selection, resource allocation, verification, and policy enforcement, and would learn from experience when to step in and when to let inference proceed directly.

Characterizing Web Search by Conversational LLM Agents: From Search Decisions and Strategies to Results and Responses

Mahsa Amani, Seungeon Lee, Abhisek Dash, Asmaa El Fraihi, Yunah Jang, Elisabeth Kirsten et al. Conversational LLM agents rely more and more on web search, but little is known about how they decide to search, write queries, and use the results. This study covers ChatGPT, Claude, Grok, and DeepSeek, combining real user conversations with controlled experiments through each platform's API. Decisions to search vary widely across platforms and models, and searching more often does not necessarily produce better answers. The agents use different querying strategies, and each platform's search engine favors certain domains. Answers are mostly grounded in search results, but some claims draw on results that are not cited, which raises attribution and reliability concerns.

A frontend-backend architecture for tool calls in full-duplex speech models

Ke Hu, Slyne Deng, Chen Chen, Elena Rastorgueva, Edresson Casanova, Punit Kumar et al. Full-duplex speech-to-speech (S2S) models support natural, low-latency, interruptible conversation but have no clean way to call external tools. In the proposed architecture, a duplex speech-to-text frontend learns to emit a delegation token and streams its speech-recognition transcript to a text-based backend LLM that makes the tool calls; the results are injected back into the frontend through a lightweight prefill-and-repeat mechanism and spoken via streaming text-to-speech. Because the frontend needs minimal modification, turn-taking and interruption handling are largely preserved, and single-turn evaluation shows 92-97% tool-call recall with 81.2% accuracy at rejecting irrelevant calls. With a large backend such as Qwen3-235B-A22B, the system is competitive on Full-Duplex-Bench-V3 and significantly outperforms GPT-realtime-mini and Qwen3-Omni-30B-A3B-Instruct on EVA-Bench.

Do AI Agents Understand Computer Architecture?

Ambika Sharan, Grigory Chirkov, Soheil Abbasloo Reports of AI agents designing hardware show that designs improved, but not whether the agent reasons about the machine or simply searches over knobs whose meaning it never grasps. AutoTuring gives the same agent the same 15-dimensional accelerator design space twice: once as named architectural parameters with simulator counters, and once as anonymous variables on [0,1]. The evaluator and reachable optima are held identical, so the performance gap isolates the value of meaning. On nine FP16 matrix-multiply kernels, the informed agent beats a modeled H200 by 5.4% and its blind counterpart by 12.3% on average while using 70.1% fewer simulator calls, yet a critic loop recovers most of that gap for the blind agent and adds nothing for the informed one, suggesting architectural knowledge and structured critique act as substitutes rather than complements; the authors label these preliminary results from five to six runs per condition.

MAGS: Multi-agent Auto-formalization Guarantees Safety for Agentic Outputs

Albert Wu, Nicholas Roberts, Tzu-Heng Huang, Haoran Lin, Gil Friedman, Sungjun Cho et al. LLM coding agents produce programs faster than humans can review them, and fuzzing, static analysis, or LLM-based verifiers cannot cover every edge case. MAGS is a multi-agent framework that uses Dafny as a verification-aware intermediate representation. It formalizes and freezes human-audited APIs and safety requirements, translates generated code into Dafny, repairs violations using verifier feedback, and compiles verified programs back to executable code. Across 100 CUDA kernels, 100 terminal scripts, and 20 robotic-arm tasks, it produced programs with non-trivial safety guarantees against the frozen specifications in all 220 cases, though independent evaluations revealed failures where the auto-formalized semantics did not fully capture the intended behavior.

Closed-World Resolution Against Tool Hallucination in LLM Agents

Laxmipriya Ganesh Iyer Tool-augmented large language model (LLM) agents sometimes call tools that do not exist or pass arguments no schema declares. Tool-selection and gating defenses cannot catch this because they assume the call refers to a real tool. Framed mainly as a measurement study, the work gives a five-class taxonomy of tool hallucination, a training-free closed-world resolver called Resolution Rung that checks registry membership and signatures, and a proof that this check must come before any gate. Across ten hosted models it records 322 hallucinations, mostly on the unconstrained raw-JSON surface, and finds that model scale does not help, with a 675B model faring no better than a 7-8B one. On the Model Context Protocol (MCP), where merging servers creates name collisions and shadowing, it finds 154 more hallucinations, including from frontier models that were clean on a single registry, and releases the Hallucinated-Tools Benchmark (HTB).

An Architecture for Long-Horizon Agents: Levels, Ticks and Cascaded Intelligence

Erik Nijkamp, Anurag Koul, Egor Pakhomov, Bo Pang Language-model agents given tasks that span days or weeks must outlast any single context window or process, and the authors argue that the ability to run continually without forgetting belongs in the harness rather than the model. They derive seven bottlenecks of the long-horizon setting and answer them with a three-part architecture: levels indexed by time scale, each keeping a bounded summary file of the level below; a clocked 'tick' as the unit of autonomous action; and cascaded intelligence, which escalates work to a more capable model only after it fails review. In a ten-day campaign with a human checking in once a day, an agent built this way reproduced a published reinforcement-learning result while keeping the thread across every context reset and session boundary. Operating knowledge the agent wrote early in the campaign changed its later behavior without any change to model weights.

EconSkills: Studying Skill Transfer and Retrieval for Web Agents on Live Economic Data

Yinzhu Quan, Zefang Liu Web agents often revisit the same sites, yet evaluations usually discard the procedures learned from earlier successes. EconSkills distills verified EconWebArena trajectories into parameterized standard operating procedures for retrieving live economic data. Each skill records its scope, navigation steps, site-specific guidance, verification checks, and recovery steps, with instance-specific values replaced by placeholders. In controlled transfer, matched skills raise success over no-skill prompting and shorten successful runs, and abstracted skills are substantially more effective than replaying raw trajectories, but when the agent must retrieve skills from a full library, results are only on par with the no-skill baseline because approximate matches on uncovered tasks cancel out the gains on covered ones.

Self Improvement via Fast Tree-search

Xinghong Fu, Aravinth Kulanthaivelu, Yutaro Yamada Coding agents can rewrite their own implementations in a self-improvement loop, but existing approaches are expensive, mainly because each candidate self-modification is evaluated by re-running benchmark tasks. Recursive Self Improvement via Fast Tree-search (SIFT) adds an LLM-as-a-judge that compares candidate patches pairwise and aggregates the win-loss record with a regularized Bradley-Terry model. The resulting strength scores guide which candidates a lightweight tree search expands next, and expensive benchmark evaluation is reserved for the most promising ones. SIFT outperforms existing tree-search self-evolution frameworks on the full Polyglot benchmark while using significantly fewer CPU hours, less wall-clock time, and lower API cost.

When Hiring Becomes Agent-Mediated: Evaluating Access and Recurrence in Two-Agent R\'esum\'e Screening

Jian Gao, Hang Jiang Résumé screening is usually automated as a single model call that judges a résumé-job pair, and the authors test a two-agent alternative in which an employer-side agent and a candidate-side agent exchange evidence and update their judgments. On 600 constructed résumé-job pairs with GPT-5.5 and Claude Opus 4.7, two-agent screening advances more applications overall. On a pool of 191 borderline pairs, pass rates rise from 4.5% to 26.2% and from 6.5% to 16.1% respectively. The change is not a uniform loosening, because decisions flip in both directions and no one-call threshold recovers the applications that two-agent screening consistently selects, which suggests that the screening procedure, not just the model, shapes who reaches human review.

Continual Enterprise World Model Discovery in Dynamic Systems

Shambhavi Mishra, David Vazquez, Perouz Taslakian, Marco Pedersoli, Jose Dolz, Issam H. Laradji In enterprise systems, updating one field can trigger organization-specific business rules that set other fields, create records, or start approvals, so an agent cannot predict the effects of its own actions without knowing those rules. The authors study how an agent can discover these hidden rules by acting on records and observing the outcomes, then revise its world model as the rules change. They introduce EnterpriseWorldShift, built on a live ServiceNow environment with 25 hidden rules and four versions of the same world in which a rule is modified, then added, then removed. Their Continual Discovery Agent (CDA) carries its world model from one version to the next and predicts the effects of hidden rules more accurately than looking them up for each question, by up to 8.98 IoU points, without querying the running system.

DeltaSelect: Affordable A/B Testing for Coding Agents

Nicholas J. Conn cross-listed Full coding-agent benchmarks are expensive and noisy for the frequent baseline-versus-candidate comparisons developers make. Resampling DeepSWE's published trials showed that only 19.5% of tasks (22 of 113) reliably track full-benchmark performance from a single run. DeltaSelect is an open-source method that picks tasks whose one-run results correlate with full-benchmark performance, maps partial verifier scores onto a common scale with linear regression, and selects a fixed task set within a dollar budget. In a case study revising custom skills and instructions for gpt-5.6-luna at low reasoning effort, 13 evaluations cost USD 27.86 in total, and the adopted version was 58.1% cheaper to run than the initial one (USD 1.75 versus 4.18) with a higher but not statistically significant calibrated score (42.36% versus 36.46%).

SIMLIFE: Pattern Understanding for Long-Horizon Human-Agent Partnership

Run Peng, Zinnia Nie, Jing Ding, Yinpei Dai, Yichi Zhang, Zengqing Wu et al. Agents that work alongside people over long periods need to infer how routines form, repeat, and change, not just what someone needs right now. SimLife is a platform that simulates long-term household life, with visual observations, ground-truth action logs, and synthetic dialogue with audio. On top of it the authors build SimLife-BP, a benchmark of 106 episodes averaging 15.49 hours and 38.57 in-game days, with 1,439 question-answer pairs that probe direct, counterfactual, noisy, and inverse reasoning about hidden behavioral rules. Frontier models often predict behavior at the surface without grasping the underlying rules: they rely on frequency heuristics rather than if-then reasoning over evidence and struggle when patterns change.

ScientistTwo: Pioneering the Human Knowledge Frontier with Autonomous AI

Jaehyun Nam, Jinsung Yoon, Yanzhou Pan, Yubo Wang, Rui Meng, Parthasarathy Ranganathan et al. Aiming at AI that independently advances research from a problem posed by a human expert, the authors introduce ScientistTwo, a fully autonomous multi-agent framework. Without human intervention, it establishes state-of-the-art baselines, forms hypotheses, runs experiments and automated ablations, and checks its findings through a simulated peer-review and rebuttal loop. Benchmarked on problems from papers accepted at ICLR, ICML, and NeurIPS, it is reported to produce publishable papers with verified, executable codebases. The authors claim its solutions consistently beat human state-of-the-art models and that its papers receive higher average ratings than human-authored papers from automated AI reviewers.

Self-Evolving Search Index

Sangam Lee, Wonjae Lee, Sunghwan Kim, Deogyong Kim, Jaehoon Kim, Daye Nam et al. cross-listed Retrieval quality depends on the index keys that represent each document, but the best key representation varies by retrieval environment, and tuning it usually requires humans to diagnose failures and reprocess the index. SELF-INDEX lets an index evolve on its own: an Optimizer diagnoses retrieval shortfalls, selectively rewrites the responsible index keys, and validates each revision before committing it, while a Query Simulator generates new retrieval demands beyond the queries already available. Across diverse corpora and retrievers, it consistently improves retrieval performance and outperforms existing index optimization methods, and the gains carry over to more effective and efficient search agents and to agent memory systems retrieving useful past interactions.

FINSKILLOPS: A Self-Evolving Multi-Agent System for SEC Filing QA

Yanzhang Ma, Zhenghan Tai, Hanwei Wu, Sizhe Guan, Jianliang Lei, Hailin He et al. Question-answering systems over SEC filings keep hitting recurring errors in period, entity, evidence use, and calculation after deployment, and existing self-improvement methods give little control over where a fix applies or what previously correct answers it might break. FINSKILLOPS is a multi-agent system that treats post-deployment improvement as controlled behavioral maintenance. It turns evidence-grounded, typed failure diagnoses into scoped reusable skills, and each skill must pass targeted validation, regression checks on protected cases, and negative controls before admission, with versioned replacement or retirement afterward. A single frozen skill registry achieves the highest verdict-weighted correctness and reference consistency across six financial benchmarks, and evolved skills raise correctness from 3.70 to 4.55 on the authors' enhanced benchmark. In a 12-round operational study, only 6 of 33 proposed skills were promoted while the monitoring non-correct rate fell from 20.0% to 12.5%.

AutoData: Agentic Search for Pre-training Data Selection

Yan Meng, Dhruv Srikanth, Bingchen Zhao, Zhengyao Jiang, Yuxiang Wu LLM agents have been used to automate machine learning engineering by editing model and training code, but pre-training data selection has stayed outside that loop. AutoData treats data selection as heuristic engineering over per-document features such as lexical statistics, categorical labels, and perplexity. An agent searches directly over executable selection algorithms (scoring, stratification, and stochastic selection rules) and refines them using validation feedback from a small proxy model. Within an overnight search it discovered a selection algorithm that outperforms existing human-designed curation pipelines, and although the recipe was found on the proxy alone, it transferred to larger scales and improved the downstream CORE metric.

Rethinking Multi-Agent Collaboration: When More Is Less

Yishuo Yuan, Yibo Wu, Yihan Zhang, Minyuan Sun, Shenliang Li, Xinkai Ma et al. As single-agent harnesses built on large language models grow more capable, the authors ask when splitting work across multiple agents actually helps. Their systematic analysis finds that multi-agent collaboration pays off mainly on long-horizon tasks with sparse dependencies, while a single agent remains better for tightly coupled, sequential workflows. They propose SAIGE (Semantic-Aware Incremental Graph Evolution), which models collaboration as a growing graph: agent instances are spawned on demand as nodes, and edges are semantic dependencies found through content-based retrieval. On long-horizon benchmarks, SAIGE balances context efficiency against task performance, and adding more agents or deeper recursion does not consistently improve results.

Long-horizon autoformalization of a core theorem underlying MIP* = RE

Sirui Lu, Ruixuan Deng, Yanqiao Zhu, Zhengfeng Ji cross-listed Formalizing landmark mathematical results has traditionally taken specialist teams years, and long efforts suffer from statement drift and from difficulty composing proofs. FormalFlow coordinates AI proving agents under human supervision using software engineering practices, with a shared blueprint that guides nested planning, proving, and review loops. With it, the authors completed a machine-checked Lean 4 proof of the quantum soundness of the classical low individual-degree test, a core theorem underlying MIP* = RE, in 63 days, producing a 126,367-line library written entirely by agents. The formalization also corrected side conditions and intermediate errors in the original proof while preserving the published final error bound under corrected assumptions.

F$^{2}$DR: A Fine-Grained Full-Pipeline Reward Framework for DeepSearch Workflows

Bojian Xiong (Tianjin University), Wentao Ding (Baidu Inc.), Yujing Lu (Baidu Inc.), Shaowei Zhang (Tianjin University), Ling Shi (Tianjin University), Jing Liao (Baidu Inc.) et al. DeepSearch systems answer complex queries with large language models (LLMs) through a loop of planning and reflection, retrieval, and answer generation, but existing reward models (RMs) and benchmarks are built for static single-turn tasks. F2DR is a fine-grained, full-pipeline reward framework that scores DeepSearch workflows on three dimensions (Content, Trajectory, and Answer) to assess the whole process. The authors also build DeepSearch RM-Bench to evaluate reward models in this setting. F2DR achieves significantly higher evaluation consistency than self-evaluation-based baselines, and the benchmark discriminates well among existing open-source RMs.

A Dual-Process Perspective on Nudge Susceptibility in LLM-Based GUI Agents

Haya Halimeh, Sascha Kaltenpoth, Kevin B\"osch, Oliver M\"uller GUI agents built on large language models increasingly act inside interfaces designed to steer human choices, raising the question of whether digital nudges sway them too and whether built-in reasoning makes them more robust. Drawing on Dual-Process Theory, the authors ran a randomized online-shopping experiment with 3,600 agents and 21,600 simulations across six frontier models from three providers. They tested automatic (Type 1) and reflective (Type 2) nudges. Agents were vulnerable to both kinds, and reasoning reduced susceptibility to automatic default nudges but increased it to reflective social-influence nudges, changing the route by which choice architecture takes effect rather than removing it, with this pattern structured by model scale.

JustMem: Just-Enough Memory Access for Long-Term Conversations

Guanhua Chen, Yanting Wang, Wenjing Zhi, Lei Sha Long-term conversational assistants must retrieve evidence scattered across many sessions without flooding the model's context, and compressing history can discard details needed to answer. The authors describe memory access along two dimensions: discovery breadth, meaning how widely to search, and reading fidelity, meaning whether to read a compact summary or the original conversation. Their system, JustMem, stores history as compact atomic memories and chooses a strategy for each query: LOOKUP for local evidence, COMPOSE for a broader search over scattered evidence, and REPLAY for recovering the original conversation when exact details matter. On LoCoMo and LongMemEval-S, it achieves the highest mean accuracy and retrieval recall among the compared memory systems while using substantially fewer generative-model tokens to build and query its memory.

TRACE: Accountable Agentic Retrieval for Source Discovery in Digital Archives

Donghan Bian (ENC, LRE), Marie Puren (LRE, ENC), Florian Cafiero (LRE, ENC) Historical archives are hard for retrieval-augmented generation (RAG) systems because documents are OCR-degraded, span many genres and sources, and must be traceable to their origin for scholarly use. TRACE is a training-free agentic retrieval framework for accountable source discovery. It was built within the DECIDON project on French Third Republic parliamentary debates and press, and is deployed internally to 24 researchers. On HistoriQA-ThirdRepublic, a benchmark of 1,752 French historical questions over 1887 debates and newspapers, it reaches R@10 = 0.856 and MRR = 0.653 at about $0.02 per question with hosted inference. It beats sparse, dense, graph-based, and agentic RAG baselines, with the largest gains on multi-hop and cross-corpus questions.

Not All AI Agents Are Equal: Characterizing Resource and Performance Dynamics

Wonmi Choi, Minuk Park, Zhixiong Niu, Yongqiang Xiong, Chuck Yoo, Gyeongsik Yang LLM agents alternate between remote LLM API calls and local tool containers, which makes them hard to serve efficiently because latency and local resource bottlenecks interact across requests. This measurement study profiles resource use and latency under concurrent load for three agent tasks: retrieval-augmented question answering, web search, and software coding. Behavior varies widely by task, and even the same tool can have very different resource profiles. Concurrency exposes task-specific CPU, disk, and memory bottlenecks, and faster LLM responses or more CPU cores do not always speed agents up. Two optimizations built on these findings, CPU-aware tool admission and task-aware CPU allocation, improve latency on CPU-sensitive agent tasks by about 5.4x and cut average latency across tasks by about 32%.

Correct Now, Insufficient Later: Auditing Update Sufficiency in Context Compression

Guangzhe Zhang A compressed memory can answer the current query correctly while discarding details that a later update will need. The authors propose a paired-history audit: two histories share the same current answer and receive the same future update, but require different answers afterward. They run a pilot on 24 such pairs across six synthetic mechanisms, 12 memory conditions, and two model backends. A deterministic frontier selector scored 96/96 on strict reveal accuracy with DeepSeek and 82/96 with GLM, but renaming identifiers dropped late-reference adequacy from 8/8 to 94/320 transformed instances, and a label-equivariant repair that removed this naming shortcut preserved only 2/8 of the original answers, so the authors present the work as an evaluation methodology rather than a validated algorithm.

The Missing Complement: State-Conditioned Minimal Sufficient Evidence for Coding Agents

Zhexi Feng, Ruiyi Zhang, Yongbo Yang, Pengtao Xie cross-listed A coding agent halfway through an issue has already read much of what a retriever would rank highest. Ranking passages one by one for relevance can also fill the budget with variants of one fact while missing others the next decision needs. The authors define the task of recovering a minimal sufficient set of evidence given the agent's current state, and build SERBench: 500 held-out agent states from 45 repositories, where an evidence set counts only if it covers every fact the decision requires. Their MSS-Complement method uses three semantic calls to propose a jointly sufficient set, search for what is missing, and return 4-8 intact source units within 6,144 tokens, recovering a complete set for 73.0% of states at five items versus 61.4% for Qwen3 embedding with reranking; a control that ranks by similarity alone reaches 66.6%, which attributes the gain to building sets rather than ranking passages.

MATCH: Model-Aware Tool Learning with Curriculum Scheduling and Hierarchically Gated Rewards

Shihao Liu, Hao Yin, Lijun Liu, Zhengzong Chen, Yuanyuan Zhao, Fei Huang Reinforcement learning (RL) for large language model (LLM) tool calling has two problems: curricula with fixed difficulty thresholds fall out of step with the policy's evolving ability, and additive rewards give credit for arguments even when the wrong tool was chosen. MATCH addresses both with two components. Model-Aware Curriculum Learning (MACL) tracks sample difficulty as the policy improves and trains each epoch on samples near its capability boundary plus a pool of harder cases, while Hierarchical Tool-call Gated Reward (HTGR) scores tool name, argument key, and argument value as a chain in which each level earns credit only if its prerequisites hold. The same rewards drive both GRPO updates and difficulty refreshes, and MATCH reaches 72.19% and 62.87% overall accuracy on API-Bank and BFCL V3 respectively, beating the main supervised and RL baselines consistently across four backbones from two model families.

A Scalable Trust Discovery Architecture for the Internet of Agents

Song Zhang, Jiankang Yao, Hongtao Li, Xiaojun Zhang, Xugang Shen, Xin Li et al. cross-listed Current agent protocols handle tool invocation and inter-agent communication, but they leave open how large numbers of agents register, prove their identity, and find each other by capability. The proposed architecture has three layers: an Agent Root that governs trusted registries, Agent Registries for registration and metadata publication, and Agent Resolvers for distributed capability discovery and trust-aware resolution. Each agent gets a globally discoverable composite identity that binds its native identifier to a trusted registry suffix, backed by dual certificates and multi-level authentication. A prototype averages 58 ms registration latency and 25 ms discovery latency, and it handles over 19,000 registration requests and 29,000 discovery requests per second.

AdaRepair-Mem: Adaptive Experience Orchestration for Repository-Level Program Repair

Z. C. Luo, J. C. Guo, W. J. He, S. Y. Wang, J. C. Yu, F. M. Zhao et al. cross-listed Memory-augmented repository-level program repair reuses past repair experiences, but the authors find three problems: memory is heavily imbalanced across repositories, adding more memory does not reliably raise success, and stored experiences skew toward bug reproduction rather than patching or refinement. AdaRepair-Mem adds three fixes: coverage-aware retrieval that falls back to cross-repository or repair-type memories, quality-aware selection that ranks memories by relevance, historical utility, specificity and redundancy, and stage-aware routing that retrieves separately for reproduction, localization, patch generation, refinement and validation. On SWE-Bench-Lite and SWE-Bench-Verified the framework improves repair on under-covered repositories, cuts noisy retrievals, and better supports turning failed patches into working fixes. The central claim is that retrieving the right experience for the right repair stage matters more than accumulating more memory.

MTVA-Bench: Evaluating the Language Model Inside Cascaded Voice Agents

Pritish Mishra, Ishaan Kumar, Akshat Mandoli, Sudarshan Kamath Most voice agents are cascaded: automatic speech recognition (ASR) transcribes the caller, a language model decides what to say and which backend tools to call, and text-to-speech (TTS) speaks the reply. Existing benchmarks either mix recognition errors with model errors or ignore phone-call realities like transcription noise, caller speech split across messages, and required reply language and script. The Multi-Turn Voice Agent Benchmark (MTVA-Bench) tests the language model under those conditions, with an LLM-simulated caller and a mock backend that responds to the tool arguments the model actually sent; it covers 49 agents, 490 reviewed scenarios and 7 languages, and it weights task and conversation quality equally, combining deterministic tool-call checks with two LLM judges that must cite specific transcript messages. In a seven-model study, six models choose the correct tool within 6.4 points of each other, yet their overall scores span 24.4 points, with most of the gap coming from argument values, action ordering, rule compliance, and what the model says around its tool calls.

When AI Agents Commit: Cognitive Serializability Across Data, Evidence, Policy, and Authority

Jun He, Deying Yu Autonomous agents derive database mutations from reads, retrieved evidence, policy, beliefs, and delegated authority, any of which can change while the agent is still reasoning. Neither database isolation nor contract checks guarantee a single point at which the mutation and all of its inputs were valid together. The authors define strict Cognitive Serializability, which requires committed effects to admit a serial order with a logical event at which every value exposed to the derivation is unchanged, plus a weaker Effect-Compatible Cognitive Admission that recertifies an effect against current dependencies and policy. Their runtime TCT implements this with typed dependency tokens, sealed envelopes, guard-first commit transactions, and co-committed receipts, and in a falsification suite the prototype prevented all injected anomalies with 3.22 ms mean commit overhead.

AgentPProf: Semantic Profiler for Long Horizon AI Agents

Yusheng Zheng, Chaokun Chang, Yu Mao, Tianyuan Wu, Yuxi Huang, Tao Ma et al. Developers of AI agents that run for days or weeks need to know where failures happen, what triggers unsafe effects, and which tasks consume the most budget. Existing observability tools, however, focus on debugging individual runs rather than aggregating across many. AgentPProf adapts systems profiling to agents by replacing the runtime call stack with a semantic operation stack, uses recursive operation segmentation to split trajectories at task boundaries, and emits pprof-compatible profiles for flame-graph analysis. It reaches 0.764 B-cubed F1 against human annotations on CodeTraceBench, and on three problem-localization benchmarks its profiles raise mean average precision (MAP) by up to 56%.

STR-Agent: An LLM-Driven Agent for QoS-Aware Routing in LEO Satellite Networks

Bowen Lu, Mugen Peng, Yaohua Sun, Hongyu Wang, Kerui Guo, Wenjia Xu cross-listed Routing in low Earth orbit (LEO) satellite networks must cope with dynamic topologies and time-varying links while meeting diverse quality-of-service (QoS) needs, and existing schemes rarely handle service requests expressed in natural language. STR-Agent is a large language model (LLM)-driven agent that unifies intent perception, tool-based execution, experience accumulation, and reflection. Its Perception Module turns requests into structured routing semantics, and its Reflection Module adapts the service-to-routing-policy mapping based on real-time congestion and past routing outcomes, backed by a perception model fine-tuned on a domain-specific supervised dataset. In a Walker-Delta constellation simulation it cuts end-to-end delay by up to 60% versus DQ-Dijkstra, fine-tuning raises intent-understanding accuracy from 45.4% to 92.45%, and reflection removes a further 120 ms of delay at 600 Mbps.

The Organization of Inference: Information, Resource Constraints, and AI Production

Yukun Zhang, Kemu Xu, Yishen Chen Using controlled workflow experiments on externally verified software-engineering tasks, the authors study how the division of token budget and task information across stages of an AI workflow affects success. Direct execution succeeds on 59.6% of tasks at both 12,000 and 24,000 logical-token ceilings, while planning under information constraints rises from 36.2% to 51.2%. Letting a read-only planner see the task issue adds about 16 points at 12,000 tokens, and at 24,000 tokens task-informed planning shows a 29.6-point advantage over direct execution. Downstream execution accounts for 89.9% of the planning workflow's extra token use, and the authors conclude that scale sets a system's capacity while workflow and information structure determine how productively that capacity is used.

SkillAA: Attribution-Guided Skill-Graph Updating with Targeted Validation and Rollback

Ziqiao Shang, Ling-Yue Ge, Lan-Zhe Guo Methods that improve a language-model agent's external skills often edit them directly from failed rollouts, with no structured way to trace a failure to the part of a skill that should change. SkillAA (Skill Abductive Attribution) represents skill applicability, execution, and composition for a frozen language model in a single graph. It contrasts successful and failed executions to route candidate repairs to specific graph objects, edits only that local structure, and screens changes through a Local Gate and a Big Gate before committing them. With gpt-5.6-sol it reaches 81.5%, 66.7%, and 91.2% on SearchQA, LiveMath, and DocVQA, and it has the highest observed mean in every main setting.

How Do Agent Harnesses Create Value? Planning Information and Release Control in Stateful LLM Agents

Yukun Zhang, Kemu Xu, Yishen Chen Agent harnesses supply planning guidance, organize execution, and check completion. The authors measure how these components affect success, erroneous acceptance, and cost for stateful large language model agents on the Retail and Airline domains of τ²-bench. Across 265 matched cells, prewritten task-specific plans improve oracle-verified success by 7.17 percentage points over shuffled policy text of matched length, with gains concentrated on more complex tasks. A read-only terminal verifier rejects 61% of invalid Retail episodes but also withholds 17% of correct ones, at under one cent per episode. Which component matters more depends on the cost of wrongly accepting a failed episode, and at high liability a standalone verifier captures nearly all the false-pass benefit of the full planning-plus-verification stack at a fraction of its cost.

SoL-Pi: Recursively Scaling Auto-Research Loops for Efficient Agent Harness

Haozhe Liu, Tian Ye, Sensen Gao, Qihang Cao, Yitong Li, Mingchen Zhuge et al. Long unattended coding-agent runs make token efficiency of the agent harness a bottleneck. The authors run automated research loops over many diverse environments to discover harness improvements, keeping four mechanisms that survive selection, covering action execution, context compaction, observation handling, and delegated reading, which together form SoL-Pi. On the 51-task EdgeBench evaluation, SoL-Pi performs comparably to the Pi harness on GPT-5.6 Sol and Opus 5 while cutting recorded token traffic by 44.7-49.0% and API cost by about one third. Estimated hourly savings are $8.75-$13.50 relative to the native Codex and Claude Code harnesses and $4.36-$5.71 relative to Pi.

Language-model groups overstate consensus when replaying human deliberation on a reasoning task

Tengfei Shao Groups of large language model agents are sometimes used to simulate human deliberation, which raises the question of whether their consensus rates match those of real groups. The authors replayed 100 held-out human groups solving the Wason reasoning task with matched agent groups, seeding each agent with a participant's pre-discussion answer and scoring humans and agents with the same code. Human full-consensus estimates ranged from 24.0% to 57.0% depending on the scoring definition, and agent groups were far more consensual, with gaps of about 34 and 44 percentage points for chat and reasoning modes under two different matching analyses. The gap persisted without early stopping and when the memorizable answer was removed, at which point reasoning-mode groups agreed almost unanimously, mostly on incorrect answers.

Chronicle: Cut-Point Replay for Regression Testing of LLM Agents

Tisha Chawla, Susheem Koul Failures in LLM agents are hard to reproduce because inference is not bitwise reproducible, tools read changing state, and multi-step trajectories rarely repeat on a re-run. Chronicle records an agent run at its non-deterministic boundaries as immutable envelopes, and its cut-point replay serves a chosen subset of those boundaries from the record while executing the rest live against new code, turning a recorded incident into a regression test that runs in continuous integration. On 6 recorded failures with simulated model boundaries, recording adds 23 microseconds per crossing, full replay makes zero model calls and is bit-stable over 20 repetitions, and the tests fail on faulty code while passing on guarded and benign changes. In a mutation study, cut-point tests catch every mutant that lets the recorded unsafe action through, while a baseline that stubs every boundary catches none.

Don't Mask the Environment: Observation Supervision Changes How Agents Explore Under RL

Juzheng Zhang, Disha Makhija, Manoj Ghuhan Arivazhagan, Vinayshekhar Bannihatti Kumar, Rashmi Gangadharaiah Standard supervised fine-tuning (SFT) of agents applies loss only to action tokens and treats environment observations as context, and the question here is whether that is the best starting point for later reinforcement learning. ActObs also supervises the observation tokens already in each trajectory, so the policy learns to predict action consequences with no extra data, parameters, tokens, or forward passes. The two approaches look similar after SFT but diverge after GRPO: on Qwen3-4B, ActObs gives higher pass@k at every sampling budget on Terminal-Bench 2.0, on Qwen3-8B it gains +3.4 points at pass@16 at some cost to pass@1, and it adds +4.2 points at pass@1 on the unseen aider-polyglot code-editing tasks. The analysis attributes this to action-only training degrading environment prediction below the base model, while joint supervision keeps more entropy during RL and needs less policy movement.

RAFT: A Stateful Retrieval-Augmented Framework for Troubleshooting Agents

Mingxuan Zhang, Xiaowen Wang, Anupma Sharan, Zhengyi Chen, Chenyu Diana Zhang, Shanshan Yang et al. Retrieval-augmented generation (RAG) for customer-support troubleshooting usually treats past cases as static documents, ignoring that cases progress through multiple stages. RAFT abstracts each closed case into a directed chain of timeline entries and retrieves at the entry level, returning the parent case's trajectory anchored at the state that matches the active case, with an optional graph linking similar cases. Evaluated as a retrieval layer on a synthetic benchmark built from Microsoft Learn Windows Server documentation and on real Apache Jira issues with human duplicate labels, it improves Case Hit over vanilla RAG and GraphRAG at every stage of case progress, with statistically significant gains on the synthetic data and directional evidence on Jira. The benchmark, implementation, and Jira evaluation set are released.

An Empirical Study of Harness Design for Coding Agents

Run-Ze Fan, Zihao Zhang, Simin Ma, Yebowen Hu, Shouju Wang, Kaiqiang Song et al. Coding-agent harnesses are usually evaluated as monolithic systems, so the contribution of individual components is unclear. Using a lightweight harness with a fixed execution loop, the authors vary planning, action space, and context management across four models on SWE-Bench Verified and Terminal-Bench 2.1, covering 176 matched settings. Context management matters more as the context-window budget tightens, mostly by preventing overflow failures, and staging rule-based elision before LLM-based summarization is the most efficient strategy, while making elided content recoverable yields no accuracy gain. Planning shifts from an accuracy scaffold for weaker models to a cost saver for stronger ones, and bash-capable models work well with a bash-only interface at substantially lower cost, whereas predefined tools help models with weaker bash proficiency.
5 more specialized papers

Large Language Models 45

Sampling Reveals Style: Unsupervised, Training-Free Discovery of Prompt-Conditional Stylistic Axes in LLM Activations

Ajit Mallavarapu, Ziwei Gu Finding which stylistic dimensions a large language model (LLM) encodes for a given prompt usually requires supervised contrastive data. The proposed training-free alternative samples many completions of a single prompt at high temperature, runs Principal Component Analysis (PCA) on the pooled hidden activations, and automatically labels each axis from the generations at its poles. Validated against 245 human stylistic annotations, the top two axes on Qwen-3.5-4B-Instruct match human-requested dimensions with 72.8% precision and 43.6% macro-recall, and 75.6% of validity ratings judge the pole generations accurate to their labels. Discoverability varies sharply by model: both Qwen models and Llama-3.2-3B expose human-salient axes, while DeepSeek-7B-Chat drops to 35.3% precision because its leading components capture structural rather than stylistic variation.

Towards Proactive Detection of User-Side Implicit Conflicts in Human-LLM Dialogue

Jinqiang Wang, Tao Zhu, Huansheng Ning In multi-turn chats, users sometimes make follow-up requests that implicitly contradict their earlier intents, and a model that misses this responds inappropriately instead of asking for clarification. The authors build UC-Bench, a human-annotated benchmark for detecting such user-side conflicts, and find that existing LLMs struggle, especially when the incompatibility is grounded in dialogue history. To train small models with limited data, they propose SynUC, which represents conflicts in a constraint space and uses the SPEAKING framework to guide traceable constraint transformations; applied to WildChat, it produces the 2,487-sample UC-Data training set. Qwen3.5-4B trained on UC-Data outperforms larger general-purpose models such as Claude Opus 4.8 on UC-Bench, as well as the same backbone trained on data from existing synthesis methods.

What Do We Expect from LLMs? Mapping the Design of LLM Benchmarks

Chao Wang (Independent Researcher) Model leaderboards reveal little about how the expectations built into large language model (LLM) benchmarks are changing. The authors map 14,767 arXiv papers from January 2022 to August 2026 that introduce or update evaluation resources, using staged screening and automated full-text coding of target systems, domains, materials, conditions, and scoring mechanisms. They find a growing emphasis on action, interaction, and professional applications, with established and newer design elements often coexisting. LLM-based scoring grows in both agent and non-agent benchmarks while model-generated test materials show no comparable sustained rise, raising the question of whether expanding evaluation risks reproducing the preferences and blind spots of the models involved.

Layer-wise Curriculum Learning for Efficient LLM Compression

Donggeon Lee, Dooyeon Na, Seungmin Oh, Jongbin Ryu Compressing large language models by transferring knowledge from a teacher to a smaller student is expensive in GPU memory and training time. The proposed method splits the model into segments of layers and trains them with a curriculum that starts with easier optimization tasks and moves to harder ones, based on a theoretical analysis of how errors accumulate across layers. It also uses multi-threaded feature caching to handle mismatched features between layers and keep the GPU busy. It reports state-of-the-art compression while cutting GPU memory use and training hours by more than 50% on BERT and GPT-2, and it beats other pruning methods on LLaMA-family and Qwen models given the same training time, while using less memory.

Block Parallelism For Efficient Distributed Long-Context Diffusion Language Model Training

Tarun Suresh, Pranshu Chaturvedi, Hangoo Kang, Parth Shroff, Ishan S. Khare, Hermann Kumbong et al. Block diffusion language models (BDLMs) generate text block by block, denoising all tokens within a block in parallel. They are costly to train at long context because standard context parallelism (CP) sends large amounts of attention data and gradients between GPUs. Because the training objective can be computed separately for each target block, the authors introduce block parallelism (BP), which gives each block's denoising computation to one GPU, and context-sharded block parallelism (CSBP), which also splits the shared clean text across those GPUs. At 256K context on 16 H200 GPUs, CSBP speeds up fine-tuning by 1.18 to 1.45x (1.61x at 512K), and it speeds up DFlash2 speculative-decoder training by 7.59x at 1M context. In matched 12-hour DiffusionGemma 26B-A4B runs it scores higher on SWE-bench Verified and Terminal-Bench Lite at every checkpoint.

Why Pretraining Fails to Share Cross-Lingual Knowledge

Adam Gaber, Uriel Dolev, Elisabeth Fittschen, Bobby Cheng, Yuval Marton, Leshem Choshen Large language models transfer surprisingly little knowledge between languages. By pretraining 360M- and 7B-parameter models, the authors show this weakness appears during pretraining and persists under standard fixes. In a controlled test using two copies of the same language with identical text but separate, non-overlapping token vocabularies, separate vocabularies alone were enough to keep knowledge siloed, even between identical copies. Mapping languages onto shared tokens through simple word-by-word translation substantially improves transfer, recovering up to 12.6% of native-language learning efficiency, 14 times the baseline.

How to Guide Your Language Flow

Rohit Dilip, Tianrong Chen, Yuyang Wang, David Van Valen, Joshua Susskind, Miguel Angel Bautista Guidance methods such as autoguidance improve flow-matching models by contrasting a strong model with a weaker one, but they cost an extra forward pass and give no reliable way to ensure the two models share similar dynamics. The proposed probe guidance builds the guidance signal from probes on the frozen internal states of an existing diffusion model, which removes the extra forward pass. On continuous diffusion language models it sets a new state of the art for unconditional generation, and it consistently improves multiple-choice question answering for a 1.7B-parameter model. Using the probes to study classic autoguidance, the authors find that the weak model must come from a low-entropy region of training, which sheds light on why autoguidance works.

Bayesian Optimization with Rich Auxiliary Information via LLMs

Tejus Gupta, Efe Mert Karag\"ozl\"u, Rohit Sonker, Barnab\'as P\'oczos, Jeff Schnieder Bayesian optimization (BO) normally uses only function evaluations, even though real problems often come with richer side information such as training curves, expert notes and images, or prior beliefs about where optima lie. The authors show that large language models (LLMs) can exploit this auxiliary information and develop three methods for bringing it into BO. On hyperparameter-optimization benchmarks and a real-world nuclear fusion optimization task, the methods consistently outperform both standard BO and existing LLM-based optimizers.

Sample Count Is Not Enough: Candidate-Generation Strategy Shapes the Energy and Performance of LLM Test-Time Scaling

Mobina Kashaniyan, Ali Jannesari Test-time scaling methods that sample multiple candidate answers are usually budgeted by the number of candidates N. That number does not say whether the candidates come from one batched call or several sequential calls. With Phi-3-mini and Qwen2.5-1.5B on 500 GSM8K prompts, raising N from 1 to 8 improves accuracy by 8.4 and 18.4 points, and the authors then fix N = 8 and compare four generation schedules. On A100 GPUs, eight serial calls used 4.64-4.86x the GPU energy and had 5.77-6.12x the 95th-percentile latency of one batched call, a pattern that also held in SciQ experiments on V100s. The authors recommend batching independent candidates into fewer calls when memory allows, and reporting generation schedule and GPU metrics alongside accuracy.

QVAC Genesis III: A Large-Scale, High-Quality Open Synthetic STEM Corpus for Efficient Language Model Pre-Training

Davide Vitabile, N. Ranjan, Akshay Nambiar, Kamal K. Gupta, Amril Nazir Small language models for edge and on-device use need pre-training data that teaches a lot per token, and open STEM-focused synthetic corpora for this purpose are scarce. QVAC Genesis III is a 191.43B-token synthetic corpus covering 19 STEM domains, generated by a teacher model that uses a weak edge-scale student as its signal. The student's failures become corrective explanations, and its successes are expanded into contrastive reasoning over every answer option. In from-scratch ablations with 1.7B-parameter models, training on the corpus beats both Cosmopedia-v2 and Cosmo-1B on ARC, GPQA Diamond, and MMLU STEM, with gains of up to +28.57% on ARC-E and +21.35% on ARC-C.

From Parameters to Behaviors: A Survey of Model Fusion for Large Language Models

Shuo Cai, Yanggan Gu, Zihao Wang, Yuanyi Wang, Yibo Yan, Wenjun Wang et al. Model fusion combines the capabilities of several source models into a single target model, and the pool of candidates keeps growing, with Hugging Face hosting more than 2 million models as of June 2026. Existing surveys cover only parts of this area and lack a unified definition or taxonomy. This survey defines model fusion and organizes prior work into three levels: parameter-level, representation-level, and behavior-level fusion. It also reviews the related metrics, benchmarks, and applications, and it outlines open challenges and future directions, accompanied by a curated paper list.

Form Over Content In Gradient-Based Data Attribution Methods

Sunwoo Kim, Seokwon Jung, Sohyung Kim, Seong Joon Oh, Alice Oh Gradient-similarity data attribution is widely used to analyze and select LLM training data, but it is debated whether it detects task-relevant skills or mostly surface form. The authors render benchmarks in different answer formats so that task and format vary independently in supervised fine-tuning data, and show that gradient alignment follows answer format rather than task. Benchmark pairs that share a format reach a disattenuated cosine near 0.4, while the same benchmark rendered in different format classes scores near 0.0. This pattern holds from early pretraining checkpoints through post-training and across model scales and families, and the released selections of the gradient-based LESS data selection method over-represent each target's own answer format.

The Complexity Kink: A Prompt-Side Structural Complexity Index for Code-Generation Reliability

Michael Hernandez, Tian Zhao Measuring complexity on generated code can mislead, because a hard prompt may produce a short program that simply fails. The authors define a six-dimension structural-complexity index scored on the prompt before any code is generated, rate 5,000 Python prompts with four LLM raters (intraclass correlation 0.872), and evaluate 21 models on every prompt for 105,000 generations. Pooled pass rates change abruptly at a composite score of 13.75, but this is not a universal failure cutoff: controlling for task type moves the breakpoint to 10.75 and shrinks the gap between the two regimes from 7.6 to 2.1 points, and per-model fits differ in direction. The authors present the index as a pre-generation measurement tool and the analysis as observational, not causal.

PrefixBench-H100: Characterizing Prefix Reuse and Time-to-First-Token in H100 LLM Serving

Omkar Shewale, Deepak Kumar, Divakar Kumar Yadav cross-listed Inference runtimes such as vLLM and TensorRT-LLM can reuse cached key-value (KV) state for repeated prompt prefixes like system prompts, retrieval templates, and multi-turn conversations, but it is unclear when this actually improves serving performance on modern accelerators. PrefixBench-H100 is a reproducible benchmark on a single NVIDIA H100 that varies shared-prefix length, suffix diversity, arrival pattern, concurrency, output length, and cache configuration across synthetic, chat-style, and retrieval-style workloads, measuring time-to-first-token, inter-token latency, throughput, cache hits, and GPU memory. It maps the regime where prefix reuse substantially cuts first-token latency and the regime where cache pressure erodes those gains. Cache effectiveness turns out to be largely insensitive to concurrency and output length, and the remaining differences between runtimes come from the scheduling layer rather than the cache itself.

Evolution or Illusion? Rethinking Evaluation in LLM Evolutionary Search

Tal Oved, Roi Pony, Oshri Naparstek, Udi Barzelay LLM-driven evolutionary search finds programs by launching seeds and iteratively refining each one, yet papers typically rank methods at a single budget, often one seed run for a fixed number of iterations. The authors evaluate three evolutionary search strategies on five commonly used optimization tasks across a full grid of seeds and iterations. They find that the best way to split a fixed budget between more seeds (width) and more iterations (depth) depends on the strategy, the task, and the total budget. Strategy rankings change with budget: on one task the strategy that looks worst with one seed is best with forty, and on another the best iteration count is well below common practice, so the authors propose a protocol that reports the full seeds-by-iterations frontier.

Reproducibility is not construct validity: LLM measurement of institutionally situated communication

Veronika Batzdorfer (KIT), Carlo Romano Marcello Alessandro Santagiustina (ALMAnaCH, m\'edialab, Sciences Po) Large language model (LLM) annotations can be highly reproducible without actually measuring the construct they are meant to capture. Using the European Commission's AI Act consultation, the authors link stakeholders' structured survey answers to their free-text submissions and find that LLM annotations of the text are highly reproducible (intraclass correlations above 0.99) yet converge only weakly with survey-reported measures of the same construct. The gap varies systematically by group: business associations express more concern about AI risks in their text than in their surveys, while public authorities show smaller or negative gaps, and the gaps are similar among neighboring European countries. The authors call for validation procedures that test reproducibility, construct validity, and effects of communication context separately.

Zarya: A Hybrid Autoregressive--Masked Diffusion Language Model with Flexible Training and Dual-Mode Inference

Leonid Sinev, Ilya Koziev, Vladislav Leshchuk Autoregressive language models generate one token at a time, while masked diffusion models decode in parallel but cannot reuse the key-value (KV) cache and can produce incoherent text. Zarya trains one model on both an autoregressive and a masked-diffusion objective, organizing training data into variable-size slots with a curriculum that moves from fine-grained autoregressive learning toward coarse-grained diffusion learning. At inference it supports either diffusion sampling or a slotted speculative decoding mode that selects slots by diffusion and fills them in autoregressively with full KV cache reuse, and a model trained under any configuration can be deployed in either mode. Models with 0.6B, 1.7B, and 4B parameters are released publicly along with results on standard benchmarks.

D-Quant: Driftable Entropy Coding for KV Cache Quantization

Yi Su, Hong Liu, Guanghua Yu, Jianchen Zhu The key-value (KV) cache is a major memory and bandwidth bottleneck when serving large language models, and fixed-width quantization loses information quickly at low bit widths because a b-bit code offers only 2^b levels. The authors observe that after rotation and normalization, KV values roughly follow a normal distribution, so entropy coding could spend fewer bits on common values, but its variable-length output does not suit highly parallel attention kernels. D-Quant introduces a drift mechanism that converts each token's entropy-coded representation into a fixed-size bitstream, which keeps memory layouts regular and allows parallel dequantization inside attention kernels.

Evaluating Communicative Success in Machine-Translated Conversation

Faiz Ghifari Haznitrama, Alice Oh Interpreter agents built on machine translation (MT) now mediate live conversations, yet they are evaluated with sentence-level fidelity metrics that ignore whether the communication actually succeeds. The authors propose a three-layer checklist-and-judge framework that scores semantic, pragmatic, and cultural-social success in single-turn and interactive multi-turn settings with simulated users, and they validate it through controlled perturbations, cross-judge comparisons, and human annotation. Across 10 interpreter setups and 5,624 OpenSubtitles-derived scenarios in Arabic, Bengali, Indonesian, and Korean, success declines consistently from the semantic to the pragmatic to the cultural-social layer, and conventional MT metrics miss failures among the stronger interpreters. Adding scenario context, structured instructions, and cultural context to prompts improves communicative success, though the gains vary by setup.

The Life of a Token: from Words to Bits on the Wire

Davide Avesani (CEDRIC - ROC), Pengwenlong Gu (CEDRIC - ROC), Sotiris Skaperas (Cnam), Stefano Secci (CEDRIC - ROC) cross-listed As LLMs grow to billions or trillions of parameters, training runs across thousands of connected accelerators, making the network between them a critical but often opaque component. This tutorial follows words as they become tokens, then vectors, then network traffic in high-performance computing (HPC) training systems, using examples from Dante's Divine Comedy. It combines architectural analysis with analytical traffic models and worked numerical examples to show how model architecture, tokenization, embeddings, and parallelization strategies shape the volume, structure, and timing of network traffic. It closes with practical guidance on the network capacity LLM training requires.

Beyond Depth Truncation: Controlled Evaluation of Depth Utilization in Recursive Language Models

Ha Van Dau, Thanh Tung Khuat, Nguyen Thanh Dung Depth-recurrent language models apply a small stack of layers repeatedly. Studies of these models, and of layer pruning, usually test whether a model uses its depth by cutting depth at inference and measuring how fast quality drops. The authors argue this slope mixes three effects: fewer layer applications, less distinct computation, and an output head reading from an out-of-distribution internal state. It is usually read as reflecting only the second. They propose the Depth Control Protocol (DCP), which uses controls that isolate each factor, applies the same interventions to dense transformers to rule out measurement artifacts, and adds a training intervention to test causality.

DeepSeek-V4.1-Flash: Pushing the Limits of KV Cache Compression

DeepSeek-AI, :, Anyi Xu, B. Li, Bangcai Lin, Bing Xue et al. Long-horizon agent workloads are input-heavy, so the compute cost of prefill and the size of key-value (KV) caches strain GPU high-bandwidth memory, SSD capacity, and data-transfer bandwidth. DeepSeek-V4.1-Flash is a multimodal Mixture-of-Experts (MoE) model with 552B backbone parameters and support for one-million-token contexts. Its Causal Encoder-Decoder (CED) architecture activates 16B parameters per token during decode but only 8B during prefill. Combining cross-layer KV cache reuse in Compressed Sparse Attention 2 (CSA2) with FP4 KV caching shrinks the cache that always stays in GPU memory to 890 bytes per token, about a quarter of DeepSeek-V4-Flash's footprint, while a deployment technique called SWA Bounded Replay cuts the persistent cache on SSD or host memory to roughly an eighth; the model was pretrained on 45T multimodal tokens, reportedly outperforms its predecessor on text and multimodal agentic tasks, and its checkpoints are publicly released.

Past, Future, All at Once: Mitigating Stability-Plasticity Dilemma via Post-hoc JANUS Rectification

Zhilong Zheng, Letian Tao, Yang Guan, Yujie Yang, Wei Xiong, Kehua Sheng et al. Fine-tuning foundation models on new tasks causes catastrophic forgetting, and existing parameter-efficient remedies impose an overly restrictive subspace orthogonality condition. JANUS is a post-hoc weight correction that works with any fine-tuning method: it projects parameter updates into the Jacobian null space, which achieves parameter-space orthogonality. The authors show this is the necessary and sufficient condition for preserving prior performance to first order. A multi-step adaptive rectification scheme compensates for the Jacobian approximation holding only locally, ghost projection and sequence-level singular value decomposition compression keep time and memory costs low, and experiments show it recovers forgotten knowledge across fine-tuning methods while keeping the gains on the new task.

Tailored to you: longitudinal effects of personalising language models

Canfer Akbulut, Justine Breuch, Arianna Manzini, Lujain Ibrahim, Matija Franklin, Roma Patel et al. Little is known about how sustained use of personalized language models shapes people's attitudes, their behavior, and their lives outside the chat. In a five-day study, 992 participants sought daily advice from one of three models: a non-personalized baseline, a memory-based model conditioned on prior conversation history, or a survey-based model conditioned on a pre-study intake survey. Many changes over time came from repeated exposure rather than personalization itself, but the two approaches diverged: memory-based participants disclosed more about themselves and rated the model as less creepy, while survey-based participants reported more regret about sharing personal information. The authors discuss what these differences mean for the responsible design of personalized AI systems.

Think Thrice Before Reranking: Multi-perspective Evidence and Reasoning Integration for Text Reranking

Lijun Liu, Zhengzong Chen, Wenyan Li, Yuanyuan Zhao, Fei Huang cross-listed LLM-based reasoning rerankers usually follow a single reasoning trajectory. That makes their rankings vulnerable to reasoning errors and blind to the many signals behind document relevance. MERIT-Rank scores each query-document pair along several complementary trajectories in a Multi-Trajectory Reasoning Space (MTRS), merges them with a joint reranker, and is trained with Progressive Rank Policy Optimization (PRPO), a staged scheme that first stabilizes the trajectories and then keeps improving ranking quality. It beats competitive baselines on both reasoning-intensive and traditional retrieval benchmarks, and its 4B model outperforms most 7B and even 32B rerankers on BRIGHT.

To Copy or Not to Copy: Controlling Speculative Decoding via Intrinsic Model Signals

Roy Eisenstadt, Ido Cohen, Edo Cohen-Karlik, Lior Wolf, Itamar Zimerman Speculative decoding (SD) speeds up large language model (LLM) inference, but it forces a choice between two ways of drafting tokens. Neural drafters such as EAGLE3 are robust across text types, while context-based copying is faster when the output repeats long spans of the input. The authors find that existing copy-based methods fire on accidental n-gram overlap that does not reflect any real intent to copy, and these false positives reduce throughput. SwitchSD trains lightweight probes on the target model's internal representations to detect genuine copy intent (AUC above 0.99) and switches between neural drafting and copying on that signal, delivering throughput gains of up to 15% over EAGLE3 across Llama and Qwen models.

Is It Still Worth Training a Classical Model in the Era of LLMs? A Crossover Benchmark on Tabular Data

Kaihua Ding Large language models (LLMs) can now label tabular rows from a plain-English description without any training, which raises a practical question for business prediction problems: should you prompt a frozen model, or collect labels and train a classical one? The authors measure the labeled-data crossover, the training-set size at which a trained classical model's learning curve overtakes a frozen LLM's flat error. They aggregate 126 independent student evaluations of small GPT models under eight prompting configurations on 18 tabular datasets and compare them against learning curves for six classical model families. Even when the LLM is given its best prompt configuration, a trained classical model wins with no more labeled data than is already on hand in 86% of cases, with a median crossover at about 6% of the training set, and the authors recommend collecting a few hundred labels and training a gradient-boosted model.

Placement Is Free, Composition Is Not: The Latin Square as a Provably-Balanced Construction for Heterogeneous Sequence-Mixer Stacks

Taebong Kim, Youngsik Hong, Minsik Kim, Sunyoung Choi, Jaewon Jang, Minseo Kim Most Transformers repeat the same attention mechanism in every layer, and when different sequence mixers are combined it is hard to tell whether gains come from which mechanisms are used or from where they are placed. The authors release Aether-7B-5Attn, a 6.59B-parameter mixture-of-experts model (about 2.98B active) whose 49 layers arrange seven sequence-mixing mechanisms as a 7x7 Latin square, so each mechanism appears exactly once in every row and column. They test the principle on a parameter-matched 700.9M-parameter proxy with a 4x4 Latin square and eight seeds per arm. Rearranging a distributed heterogeneous stack into a periodic cycle changed validation loss by only 0.16% and clustering the mechanisms into contiguous depth bands cost 0.59%, while replacing the heterogeneous stack with a homogeneous one cost 1.68%, a penalty that grew to 2.63% at 1.514B parameters.

QEncodeBench: Can Large Language Models Encode Classical Problems into Verified Quantum Oracles?

Xujun Che, Hanhan Wu, Yuchen Yuan, Chenyang Yu cross-listed Quantum algorithms such as Grover search assume the classical predicate is already compiled into a correct, resource-bounded phase oracle, and QEncodeBench measures whether large language models (LLMs) can perform that compilation for classical constraint problems. Generated circuits are checked by an adversarially self-validated verifier for full solution-set equivalence up to global phase, with ancillas restored and resource budgets enforced, and the authors show that sampled basis-state tests systematically overestimate model ability. Code models without a reasoning mode solve essentially nothing, while enabling native reasoning on the same weights improves accuracy by an order of magnitude, and the remaining failures are overwhelmingly semantic rather than syntactic. A unit-verified constraint agent and a neuro-symbolic compilation pipeline that hand correctness-critical composition to deterministic procedures close most of the gap, with the neuro-symbolic pipeline passing every evaluated instance.

Accelerating Sharded Data Parallelism at Scale with Federated Learning

Gianluca Mittone, Marco Aldinucci cross-listed Sharded data parallelism (DP), the dominant way to split data and models across GPUs when training foundation models, incurs heavy communication overhead at scale, especially on multi-tier interconnects with uneven performance. Borrowing from federated learning (FL), the authors propose FL+FSDP and FL+HSDP, which interleave sharded data parallelism with FedAvg-style aggregation. This splits large deployments into loosely coupled federation groups that exchange little inter-group traffic and keep the global batch size bounded by group size. Pre-training Llama3.1 8B on 512 A100 GPUs with identical hyperparameters, the hybrids achieve up to 8.04× faster data processing and up to 4.48 lower evaluation perplexity than their standard counterparts, which the authors attribute to reduced communication and bounded batch-size growth.

When EOS Tokens Disagree: Understanding Length Inflation in On-Policy Distillation

Yuxiao Yang, Tianrun Yu, Shangzhe Li, Kaixiang Zhao, Xuchao Zhang, Chetan Bansal et al. On-policy distillation (OPD) can make student responses grow excessively long, sometimes exhausting the generation budget. The authors trace an important part of this to termination-token mismatch: across Qwen3, Llama, and Gemma, a base student and a post-trained teacher can put their stopping probability on different end-of-sequence (EOS) tokens even when their declared stopping sets match, which suppresses the student's preferred stop action without transferring the teacher's. Aligning the decoding stopping set alone is insufficient, but treating functionally equivalent EOS tokens as a single shared stopping action substantially mitigates the length inflation in all three model families. A stage-wise analysis on K2-Horizon also reveals a separate late-run length inflation that persists after termination alignment, and an implementation of the corrections is released.

Relational Attention for Data-Efficient Language Modeling

Adrian Brasoveanu, Ece Takmaz, Jakub Dotla\v{c}il This BabyLM 2026 challenge submission tests whether relational attention, known to improve data efficiency on purely relational tasks, also helps data-constrained language modeling. It replaces self-attention with a Dual Attention Transformer (DAT) that routes object-level lexical features separately from relational information, adds a Next-Latent Prediction (NextLat) objective that pushes hidden states toward a compressed belief state, and introduces a parameter-free RoPE-based symbol-retrieval mechanism that matches learned symbol libraries. Architecture proved the dominant factor for structural linguistic generalization, with the objective secondary but significant, and full relational attention pulled ahead of simpler variants only at 100M words. On the strict 100M-word track the best model ranked 6th of 55 overall and 3rd of 55 on the NLP-task subset, with the two strongest models beating the GPT-2 baseline on most benchmarks.

An Analysis of Training-Free Self-Reported Confidence in Language Models

Lukas Meyer, Sofia Rossi, Wei Chen, Thomas Laurent, Yiming Li Whether a language model's self-reported confidence carries real signal is tested by comparing three training-free measures on 100 TriviaQA questions for two model families: confidence verbalized with the answer, post-hoc P(True), and agreement with three additional generations. After auditing benchmark errors, direct verbalization reaches AUROC 0.956 and 0.937 for predicting correctness, well above three-sample agreement at 0.765 and 0.790, and combining the two gives no reliable benefit. Several errors received unanimous sample support, showing that self-consistency can amplify shared misconceptions. Re-eliciting confidence with equivalent prompts shifts scores by 0.043 to 0.084 on average and flips 4% to 9% of decisions at a 0.8 threshold.

Deep Noir: Autonomous Steering Discovery via Architectural Chronometry in Transformer Models

Frank E. Bobe III, Gregory D. Vetaw, Darshan W. Bryner, Matthew G. Cook, Jose L. Salas-Vernis Activation steering changes LLM behavior at inference time, but choosing which layers and heads to steer and how strongly is still done by hand. Deep Noir automates this using Logit Lens convergence and causal head-level attribution to discover steering parameters across nine models from 1B to 9B parameters. It reports a 16.7 percentage-point gain on spam classification at 1B, gains of 21 to 42 points at 7-9B across four architectures, and 13.1 points on SST-2 sentiment where RepE without head masking fails to beat the baseline. Steering is also shown to open a predictable prompt-injection attack surface whose vulnerability grows monotonically with steering magnitude.

On-Demand Attention: Language Models Know When to Recall

Haibo Feng, Ruiqi Liang, Hanyang Peng, Shiqi Yu Full-attention decoding reads the entire growing history at every step even when it contributes little to the next token, which is costly for long-context reasoning and agentic workloads. On-Demand Attention (ODA) builds on the finding that a pretrained model's decoding states already predict how much a global read will help, and trains only a lightweight recall head that decides when to invoke global attention while otherwise decoding locally. Pretrained weights stay frozen and the full KV cache stays available for later recall, and a GPU-side conditional execution path in vLLM turns the skipped reads into real decoding speedups at long context. Across Qwen and Gemma models, including hybrid-attention backbones, selective recall recovers most of the performance lost under local attention while substantially reducing global reads.

dQwen3.5: Hybrid-Attention Diffusion Language Models

Anton Xue, Litu Rout, Aditya Akella, Adam Klivans, Sujay Sanghavi, Sanjay Shakkottai Diffusion language models (DLMs) are usually adapted from full-attention autoregressive transformers, but newer autoregressive models interleave attention with RNN layers that are structurally causal and hard to make bidirectional. The dQwen3.5 family adapts Qwen3.5 hybrid backbones at 0.8B, 2B, 4B, and 9B scales into DLMs to test whether the mismatch matters. Against a full-attention control, the hybrid backbone reaches a given training loss in about half the tokens, and the resulting models behave like full-attention DLMs in any-order decoding and perform strongly under parallel decoding.

Embedding Models Measure in Peculiar Ways

Juri Opitz, Andrianos Michail Embedding spaces define semantic similarity and distance, and this study tests whether they reflect physical measurements of mass, distance, time, and volume, where equivalence and distance have a unique objective definition. The authors find that physical measurement is only weakly modeled in embedding space, with peculiar measurement patterns appearing instead. Further analysis indicates that representations of measurements are strongly influenced by superficial string similarity, and recalibrating similarity does not substantially improve alignment.
8 more specialized papers

Theory 38

Null importance: Disentangling relevance for interpretable machine learning

Garvesh Raskutti, Kris Sankaran, Jiaxin Ye cross-listed Feature importance in interpretable machine learning mixes together several distinct notions of relevance. The authors propose a unifying framework built on 'null importance', a population-level description of when a feature is irrelevant under a given notion: marginal or conditional statistical relevance, predictive risk, functional invariance, or causal effect. They give sufficient conditions under which these nulls coincide and counterexamples where they diverge, and they characterize which null each family of importance methods actually targets. Applications to algorithmic fairness and genomic perturbation modeling, along with simulations and case studies on image and multiomics data, show that different notions of relevance can lead to different conclusions about what a model has learned.

Evaluating Explanation Methods by the Predictors They Induce

Jacob Selb{\ae}k, Hugo L. Hammer The criteria used to judge explanation methods are hard to compare, so the authors propose a direct test: turn an explanation into a predictor by summing each feature's stated effect, then measure how well it reproduces the model's outputs on unseen data, with nothing fitted. They apply the test to partial dependence plots (PDP), accumulated local effects (ALE), SHAP, and LIME, and prove that summed partial dependence curves are the best possible additive summary when features are independent but not when they are dependent. Across 13 real datasets, 9 synthetic designs, and four model families, which method scores best depends entirely on feature dependence: PDP slightly beats SHAP under independence, as the theory predicts, while SHAP leads on dependent real data. Some widely used explanation quality metrics even prefer a deliberately damaged explanation to an intact one.

Small Enough to Know Everything: The Fully-Enumerable Transformer as an Instrument for the Science of Delayed Generalization

Yoshiyuki Ootani Tiny transformers trained on tasks small enough to enumerate every input allow exact generalization ceilings, task edits that change one variable at a time, inspection of every weight, and survival statistics over hundreds of seeds. The authors argue this makes them a scientific instrument for studying grokking, or delayed generalization. To test whether laws found at this scale transfer, a preregistered study re-measured three laws discovered at 12K parameters (a recoverability-ceiling law, a role-conflict delay law and a weight-decay response law) at 12K, 1M and 50M parameters, across 360 runs plus a 44-run control arm. The ceiling and delay laws held across the 4,000x scale span (0 of 144 ceiling violations, Spearman rho of at least 0.75 at every scale), while the weight-decay law steepened systematically with scale, which shows the test could have failed.

Parallelism, critical windows, and separations among diffusion language models

Sitan Chen, Liye Wang Diffusion large language models (dLLMs) are promoted for generating many tokens per forward pass, but how the masked, uniform, and Gaussian variants compare in parallelism has lacked theory. The authors prove that uniform and Gaussian diffusion can sample in a number of forward passes scaling with the dual total correlation of the distribution, a complexity measure that can be far below the context length and was previously only known to be achievable with masked diffusion. For a family of random empirical measures, roughly the square root of d forward passes are necessary and sufficient for uniform or Gaussian diffusion, while masked diffusion needs on the order of d passes under certain approximate score oracles, giving the first provable separation in parallelism among the three paradigms. The gap arises because critical windows in masked diffusion sampling are asymptotically narrower, not because masked models must commit to token values.

Limits of Confidence in Diffusion

Russ Webb, Amitis Shidani, Alice Bizeul, Dan Busbridge Discrete diffusion samplers, including remasking and uniform-state variants, write several token positions per step by drawing each from its own per-position distribution, which ignores dependencies between tokens. The authors prove that a step matches the training distribution only when the written positions are conditionally independent given the fixed tokens, that no product of per-position distributions can reproduce a dependent group, and that per-position marginals cannot even reveal whether a group is dependent. On ScanAndAdd, a synthetic task with a closed-form joint distribution, every group of two or more positions chosen by confidence ranking turns out to be dependent, and the generated distribution sits at 29x the sampling-noise floor in total variation even though per-sample metrics read 1.0.
33 more specialized papers

Robotics 27

GAVEL: Graph World Models for Verified and Efficient Long-Horizon LLM Task Planning

Ruiyang Wang, Hao-Lun Hsu, Swarajh Mehta, Jiwoo Kim, Zhihao Dou, Miroslav Pajic cross-listed Plans that LLMs generate for long robot tasks often break physical constraints, fail to recover from mistakes, or cope poorly with objects the robot cannot see. GAVEL keeps an explicit graph world model of object relations, what each action requires and changes, and probability estimates of where unseen objects are. It uses the model to check actions before execution and fix errors directly, calling the LLM to replan only when an error needs semantic reasoning. For instructions with several tasks, it also reorders the remaining subtasks to minimize expected search. On BEHAVIOR-1K with Qwen3-8B, it raises single-task success from 41.2% to 91.8% and multi-task success from 19.9% to 92.6%.

From Rollout to Reset: A Graph-Based Harness for Autonomous Long-Horizon Manipulation Evaluation

Jing Jiang, Yue Yang, Xinkai Jiang, Gedas Bertasius, Daniel J. Szafir, Rudolf Lioutikov cross-listed Real-robot evaluation of manipulation policies still relies on humans to reset the scene between rollouts, which costs operator time and leaves initial conditions unspecified, and the prior automated system AutoEval handles only single-step tasks. HALTER restores the scene after long-horizon rollouts by planning over a library of learned atomic reset skills. It builds a spatial scene graph online from point clouds and vision foundation models, and an LLM reasons over that graph to score the rollout, plan the reset, and verify it without task-specific labeled images. On four long-horizon tasks with a Franka arm it restores the scene in 76% of episodes versus 52% for AutoEval, cuts evaluation operator time by 72% relative to manual resets, and resets 74.7% of episodes on held-out tasks compared with 1.3% for a per-task reset policy.

Predict Before You Deploy: Offline Prediction of Quantization-Induced Task Degradation for World Action Models

Jiuyi Xu, Jinjia Guo, Meida Chen, Jing Du, Yangming Shi cross-listed World action models (WAMs) built on video-generation backbones are expensive to deploy. Post-training quantization offers many bit-width, grouping, and quantizer choices whose effect on task success is costly to test in closed loop. PreDE predicts this degradation from offline action deviations: it calibrates two thresholds on a small development set with known outcomes, then accepts, rejects, or defers new configurations. On 28 held-out configurations it decided 21, all matching the observed outcomes. In 450 real Franka Research 3 trials, W4A4 quantization gave a 1.37x action-query speedup with about 44% lower peak memory.

GLAMDRING: Gait Learning And Morphology co-Design via Reinforcement LearnING of CPGs

Amogh Joshi, Kaushik Roy cross-listed Robots for unstructured settings such as disaster sites or farms often need bodies that do not yet exist, and the right body and the right gait depend on each other. From velocity bounds, a per-actuator power budget, an actuator library, and a payload requirement, GLAMDRING returns a quadruped morphology plus a gait policy based on a Hopf-oscillator Central Pattern Generator (CPG). It trains a small, fixed number of CPG policies with reinforcement learning across the candidate morphologies and then chooses link lengths and actuators from each policy's logged operating envelope, instead of training once per design. Experiments show that co-design is needed to meet the locomotion constraints and that canonical animal gaits emerge naturally from morphology and constraints alone, backed by a real-world demonstration.

EmbodiedMind: Adaptive Data Curation and Prefix-Tree Reinforcement Learning for Efficient Embodied Intelligence

Feifan Wang, Zongbing Zhang, Yu Zhang, Lingfeng Wang, Yurui Zhu, Jin Deng et al. cross-listed Training embodied foundation models wastes compute on low-information samples, suffers from imbalanced gradients across heterogeneous tasks, and handles long-horizon credit assignment poorly because a trajectory-level reward penalizes every token equally. EmbodiedMind uses a three-stage recipe. Rejection Sampling-based Fine-Tuning (RSFT) filters out uninformative data. Iterative Rejection GRPO (IR-GRPO) keeps reinforcement learning balanced with difficulty-stratified per-task queues and a hybrid reward. Trie-GRPO organizes actions into prefix trees to estimate step-level advantages, so correct intermediate decisions are not blamed for later errors. The model reaches a state-of-the-art average of 70.02% across 18 benchmarks and substantially outperforms other embodied foundation models on long-horizon task planning.

Improving Cross-embodiment Transfer in Latent Action Models with Action-Similarity Supervision

Maxime Alvarez, Renzo Caballero, Tatsuya Matsushima, Yusuke Iwasawa, Yutaka Matsuo cross-listed Latent action models (LAMs) learn shared latent actions from action-free videos so that robot demonstrations can transfer across embodiments. However, they are sensitive to background visual noise and may encode the same motion from different robots differently. Instead of adding an auxiliary loss that predicts the ground-truth robot action, the authors train the similarity between pairs of latent actions to match the similarity of the corresponding ground-truth action sequences, so the latents need not encode embodiment-specific details. On RoboTwin 2.0, two bimanual robots demonstrate disjoint task sets and each is evaluated on the other's tasks; there, predicting latent actions instead of ground-truth actions more than doubles cross-embodiment success, similarity supervision beats the auxiliary-loss alternative, and computing similarities on end-effector motion across both robots works best.

Learning and Transferring Closed-Loop Robot Software

So Kuroki, Yujin Tang cross-listed Closed-loop robot policies are costly to design by hand, and it is unclear whether code a coding agent has improved on one task helps it write policies for new tasks. Here a coding agent writes policy code from a few demonstrations, refines it with simulation feedback, and keeps the best-validated implementations in a software archive that it reuses on new tasks. The final policy runs as frozen code with no further model calls. On four RoboCasa source tasks, iterative refinement raised mean success from 28.3% to 64.2%. On nine target tasks, mean success was 45.2% with no references, 41.5% with the initial source code, and 57.0% with the optimized source code, though initial references still did better on two of the target tasks.

MAGMA-GEN: Validated Recovery Supervision from Ambiguous Failures via Counterfactual Re-Execution

Loan Bernat (LAAS-GEPETTO), Matthieu Grard (LAAS-RAP), Ariane Herbulot (LAAS-RAP), Florent Lamiraux (LAAS-GEPETTO) When hierarchical robot systems chain high-level decisions over stochastic low-level skills, failures are ambiguous: a bad outcome might come from a wrong decision, partial observation, or a sound decision that failed physically. MAGMA-GEN turns such failed rollouts into training data by having a privileged coach hypothesize an early decision-level error and propose localized corrections or recovery actions. It keeps a candidate only if re-executing it from the same state under matched conditions actually improves downstream progress, which yields supervised examples from the agent's own failure distribution without per-step human demonstrations. On interactive long-horizon manipulation tasks in both simulation and on a real robot, it improves task success and recovery over distillation and trajectory-repair baselines under evolving task constraints.

JEPA-WAM: Connecting Generated Visual Instructions to World Action Models through JEPA Latent Representations

Tianbin Liu, Jian Zhu, Taiyi Su, Jianjun Zhang, Chong Ma, Zitai Huang et al. World action models (WAMs) add action experts to pretrained video generators for robot manipulation but follow text instructions poorly, which the authors attribute to robot datasets that pair rich visual-action trajectories with sparse, repetitive language labels. JEPA-WAM augments each instruction with several task-completion images sampled from an off-the-shelf text-to-image generator and encodes them with a frozen V-JEPA 2.1 encoder. It compresses the encodings into goal tokens that condition both the video and action experts through cross-attention. On a new real-robot instruction-following benchmark it reaches success rates of 87.3% in-distribution, 74.5% on out-of-distribution scenes, and 80.9% on out-of-distribution instructions, outperforming π0 and Fast-WAM by at least 10.0, 27.3, and 14.5 percentage points respectively.

Accelerating Visual Policy Learning with Sampling-Based Model Predictive Control

Yilang Liu, Haoxiang You, Qian Wang, Daniel Rakita, Ian Abraham cross-listed Training visual policies for contact-rich locomotion and manipulation is costly, and first-order policy gradients (FoPG) through differentiable simulation can settle into unintended contact patterns. Sampling-Guided Policy Search (SGPS) initializes a policy by behavior cloning from sampling-based model-predictive control, then alternates sampling-based refinement of action targets with short-horizon FoPG updates under perturbed initial states and randomized dynamics. A decoupled formulation keeps rendering out of the computation graph, so policies learn directly from depth observations without a state-based teacher. On a single GPU it learns locomotion, obstacle traversal, crate pushing, and bimanual carrying for simulated Unitree Go2 and G1 robots, and the distilled policy transfers zero-shot to a real Go2 that trots, crawls, clears hurdles, and switches between these behaviors using onboard depth.

A Simulation Platform for AUV Fault Recovery: Exploring LLM-Based Diagnostic Strategies

Khalid Halba, Kylie Cooper, James G. Bellingham cross-listed Autonomous underwater vehicles (AUVs) operating beyond reliable communications must recover from faults on their own, and the proposed architecture keeps deterministic layered control for normal operation while invoking a large language model as a diagnostic and recovery planner when anomaly detection fires. SPAR (Simulation Platform for AUV Recovery) couples real-time C vehicle software with an orchestration layer for physics-based fault injection, structured prompting, mission file generation, validation, execution, and LLM-judge scoring, enabling ensemble rather than single-run evaluation. Over 480 trials of a mass-shift fault, model choice dominates: a frontier model puts the correct center-of-gravity shift mechanism in its top three hypotheses in 85-90% of trials versus 60-78% for the best local model. Weaker models tend to commit early to an elevator failure, and diagnostic quality does not appear coupled to the quality of the operational decision.

HIL-UMI: Bringing Human-in-the-Loop Post-Training of Vision-Language-Action Models to Universal Manipulation Interface

Zimu Han, Yiming Zeng, Jiyao Zhang, Zihao Zhao, Yuanfei Wang, Yixiang Jin et al. cross-listed Adapting large vision-language-action (VLA) models to a specific deployment through supervised fine-tuning suffers from poor coverage of out-of-distribution states and from imitation objectives that cannot tell progressing behavior from unhelpful data, while interactive post-training normally requires running the policy on a physical robot. HIL-UMI moves human-in-the-loop post-training onto the handheld Universal Manipulation Interface (UMI): during demonstrations it queries the current policy on the same observations without executing it, and an Energy Score comparing human and policy trajectories triggers data collection in out-of-distribution regions. Low online advantage predictions separately flag segments for refining a progress-based advantage estimator, which then guides advantage-conditioned behavioral cloning. Across four real-world tasks it consistently improves over supervised fine-tuning and outperforms HG-DAgger on a table clean-up task with lower per-frame collection time.

MILER: Semantic Mid-Level Representation for Sim-to-Real Reinforcement Learning in Unstructured Autonomous Driving

Thomas Steinecker, Denis Trescher, Alexander Bienemann, Thorsten Luettel, Mirko Maehlisch cross-listed Reinforcement learning is rarely deployed for real-world driving in unstructured environments because of the sim-to-real gap. MILER trains an end-to-end policy in a custom simulator that uses a semantic mid-level representation, then at deployment uses BEVFusion on camera and LiDAR data to produce a matching semantic bird's-eye view, with a trajectory-alignment step instead of applying policy actions directly to the vehicle. The system drove 17.3 km without human intervention across two vehicles on a 3.0 km test track with obstacles, hairpin curves, off-road sections, and speeds up to 33.6 km/h, with the whole stack running on a Jetson AGX Orin.

OPTED: On-Policy Fine-Tuning for End-to-End Driving using a Render-Free Teacher

Damiano Da Col, Maximilian Igl, Peter Karkus, Kashyap Chitta, Boris Ivanovic, Marco Pavone et al. cross-listed End-to-end driving policies pre-trained by behavior cloning suffer compounding errors in closed loop, and fixing this with reinforcement learning requires expensive sensor simulation. OPTED decouples the two: a privileged teacher is trained with RL on vectorized inputs (HD map and bounding boxes) without rendering, and then supervises the camera-based student during closed-loop post-training. Applied to TransFuser and VaVAM in AlpaSim using 3D Gaussian splatting reconstructions of real driving logs, driving scores rise by 1.6x and 9.5x, and in controlled experiments it matches direct RL post-training with roughly three orders of magnitude fewer simulator interactions while staying closer to the human prior.

Workspace Models: Lightweight Robotic Memory via Saliency-Driven Supervision

Nitish Dashora, Douglas Chen, Idan Shenfeld, John Marangola, Pulkit Agrawal, Max Simchowitz cross-listed Long-horizon robotic manipulation needs memory of past events, but conditioning policies on full histories invites spurious correlations, and many existing approaches compress history with expensive vision-language model (VLM) queries during execution. This work moves the VLM queries to training time: a VLM identifies the current and historical information needed for a task, and that information is distilled into a lightweight latent called the workspace token using a set-reconstruction decoder loss. In simulation and on hardware, the workspace token serves as a drop-in replacement for observations at deployment, letting policies solve memory-intensive tasks with no VLM in the loop. The authors report that the tokens are not only more lightweight but also lead to better policy performance.

Coding Agents with an Obstacle-Aware Harness for Safe Robot Manipulation

Bingxin Xu, Yuzhang Shang, Zhen Dong, Emilio Ferrara cross-listed Coding agents can operate robots by writing the controller as a program, and this work evaluates that paradigm under a safety constraint in which each manipulation goal is paired with an obstacle the robot must not touch. The agent collides with the obstacle in most cases even though it reasons about the obstacle in its traces and the prompt forbids contact, which the authors attribute to planning: the model has no notion of a clearing route or of replanning, and does not treat contact execution as bound by the same constraint. SafeHarness adds obstacle-aware route planning, which grounds objects as bounding boxes and has the agent plan, verify, and replan waypoint routes before executing, plus obstacle-aware contact execution that selects contact positions avoiding the obstacle. It reaches 71.9% task success and 87.5% collision avoidance, exceeding the previous state of the art by 6.5% and 27.0% and amounting to 2.3x and 1.5x the results of the same agent without harnesses.
11 more specialized papers

Safety & Alignment 26

Subliminal Prompting Beyond Static Geometry: Causal Depth and Multi-Token Confounds

Barath Velmurugan Subliminal learning, in which a language model passes on a hidden trait through seemingly unrelated outputs, has been attributed to token entanglement between animal and number tokens, but existing evidence mixes several distinct kinds of measurement. Using a fixed animal-number prompting protocol on Llama-3.1-8B and Llama-3.1-70B, the authors separately measure output co-variation, static output-vector alignment, hidden-state readability, and causal control, the last by copying the answer-position hidden state from one prompt into another at five depths. Moving from 8B to 70B, static output-vector similarity predicts behavior less well, while causal donor-control AUC rises from 0.254 to 0.540, increasing for all 18 concepts. In two Qwen models, a positive association that appears when per-token scores are averaged over multi-digit numbers vanishes once number width is controlled, revealing a length confound; the authors conclude that these properties constrain token-level explanations but do not identify the training-time transfer mechanism.

PAPC: Platform Mediation for Privacy-Propagation Externalities in AI-Mediated Workflows

Tao Huang, Guosen Wu, Chen Hou, Guolong Zheng cross-listed When LLM agents act for different people on a shared platform, private information can leak before any final answer is produced: through memory writes, shared-workspace updates, messages between agents, or tool calls. The harm grows with how many parties a piece of information reaches. PAPC is a platform-level mechanism that intercepts each event that moves information and, based on policy, data origin, how widely it would spread, access privileges, and content, decides whether to allow it, release a policy-safe abstraction, quarantine the raw content, block it, or restrict further sharing. On retrieval-memory and multi-agent workflow benchmarks, it keeps deterministic tasks completing while eliminating measured exposure of exact raw values, both inside the platform and to external channels.

AUDITPLAN: Commit, Then Answer for Auditable Safety Alignment

Sai Sri Pushpa Jampani, Kshitij Mishra, Asif Ekbal cross-listed Safety fine-tuning usually scores only a model's final answer. That makes it hard to tell robust refusal apart from blanket refusal of benign requests, or from polished safety rationales that don't actually constrain the answer. AUDITPLAN has a single model first emit a compact structured safety plan, hidden from users but machine-checkable, that records a threat label, intended action, and explicit constraints, and then answer conditioned on that plan. Training uses supervised fine-tuning followed by reinforcement learning with FAITHGATE, which grants answer reward only when the plan is correct; on Qwen2.5-3B-Instruct this cuts attack success rate from 24.0% to 11.6% and over-refusal from 11.0% to 2.0%, outperforming answer-only RL, free-form explanations, and weighted-sum structured rewards, with the same trend on 1.5B, 4B, and 7B Qwen models.

The Role of Fine-grained Harm Signals in LLM Safety

Soyeon Park (KAIST), Seogyeong Jeong (KAIST), Sunwoo Kim (KAIST), Alice Oh (KAIST) Large language models' internal harmfulness representations vary across risk categories while sharing a general harm component, which leaves open what the category-specific part contributes to safety. The authors isolate a category residual that is orthogonal to the general harmfulness direction at every layer and apply activation steering with these residuals across 11 risk categories in 3 instruction-tuned models. Whether a residual encodes harmfulness varies by category in a pattern that is similar across models, whereas whether it induces refusal is more model-dependent. The residuals also increase downstream internal alignment with the shared general harmfulness representation, showing that a direction orthogonal to a concept at one layer can still amplify that concept in later layers.

Safety Beyond the Interface: Detecting Harm via Latent States in Large Language Models

Alizishaan Khatri, Chiquita Prabhu, Omkar Neogi External guardrail models add latency and compute to large language model (LLM) deployments and cannot see the model's internal state, so the authors ask whether the model's own activations already reveal harmful content. They extract activations from LLaMA-3.1-8B and train lightweight multilayer perceptron (MLP) probes with 12.6M parameters to classify harmful prompts. The probes reach F1 scores of 99% on WildJailbreak, 83% on Beavertails, and 84% on AEGIS 2.0, competitive with guard models roughly 1000x larger at lower latency and compute cost.

For Your Eyes Only: Evaluating Coordination Between Isolated Language Model Instances

Alexander Shirnin, Aleksey Kudelya As model outputs are increasingly consumed by other model instances, the authors ask whether a model can hide a signal in natural language that an independent copy of itself can detect with no shared memory or coordination training. In the For Your Eyes Only signalling game, a Sender describes two words, one of them a hidden target, and an isolated Receiver must pick the target. Seven models from four families are tested on 300 word pairs from psycholinguistic corpora, using a Double-Pass Success Rate that controls for output biases. Most models lose coordination once they must avoid detectable signals, but one frontier model stays near-perfect even after such filtering, and coordination is consistently weaker across architectures than within them.

Red-Teaming Auto Mode: Improving Blocking Classifiers Against Malign Coding Agents

Alex Remedios, Simon Storf, Fabien Roger, John Hughes cross-listed Production coding agents increasingly run behind blocking monitors that can reject each proposed action, such as Auto Mode in Claude Code and Guardian in OpenAI's Codex. These monitors have mostly been tested against accidental harm or outside prompt injection, not against a persistently misaligned agent. The authors task an adversarial agent with evading the monitors to cause catastrophic harm, such as exfiltrating its own weights, and find it succeeds through several routes: prompt injections it writes against the monitor, multi-agent attacks, and malicious context compaction. In 79% of trials, an injection attack let the agent run arbitrary bash commands past both monitors, and while design changes such as broader tool coverage, better transcript formatting, and an agentic monitor stage greatly improve Auto Mode, blocking multi-context attacks at acceptable cost remains unsolved.

From Intent to Action: Benchmarking LLM Safety in Vehicle Voice Command Authorization

Diba Afroze, Xingli Zhang, Yazhou Tu, Xiali Hei An LLM-based vehicle voice assistant must decide, before acting on a command, whether to execute it, refuse, ask for clarification, require confirmation, defer to manual control, trigger an emergency response, or make no tool call. The authors build a 202-scenario benchmark with reference decisions across this seven-class taxonomy, varying speaker role, authentication status, vehicle state, and tool availability, and test two local open-weight models and three API-based models. Agreement with the reference decisions ranges from 40.1% for Llama 3.2 3B to 89.1% for Gemini 3.1 Pro Preview, yet even the best models wrongly execute two to three commands among 161 scenarios where execution was not the right call. The authors conclude that deployments need an independent enforcement layer that checks tool permissions and vehicle state before any vehicle function runs.

SoK: Trading Agents or Market Crashers? Dissecting Robustness and Security Failures in Academic Financial LLM Trading Schemes

Mengxiao Wang, Nitesh Saxena cross-listed Security studies of autonomous LLM agents are mostly domain-agnostic and overlook high-stakes settings such as financial trading, where a compromised agent directly controls real capital in an adversarial market. FARSIGHT (Financial Agent Robustness and Security Investigation and Global Holistic Testing) evaluates trading-agent schemes on two axes. The first is robustness to market turbulence, including flash-crash-like scenarios. The second is security against three attack types: attacks on information sources, attacks on agents, and agents acting as attackers. Applied to 15 representative academic schemes, it finds that 80% fail at least one core robustness metric and all of them exhibit security vulnerabilities, and the authors argue the two failure modes are intertwined because a small misjudgment and a cheap deliberate attack can both trigger a market-wide crash.

ALIBI: Adversarial Legitimacy Injection in Binary Input against LLM Malware Analyzers

Hyeongjun Choi, Wonyoung Jung, Haehoon Seo, Sungyup Nam cross-listed LLMs are increasingly used in malware triage to summarize static evidence and issue verdicts, and that reasoning ability opens a new attack surface. ALIBI adds a small, non-executed read-only section to a compiled binary containing a coherent but false story that the program is a security product. Instead of instructing the model directly, the story reframes suspicious evidence as expected behavior, and it leaves imports and executable behavior unchanged. On 50 malicious Portable Executable (PE) samples, the payload flipped 30 of the 35 samples Gemini 2.5 Pro originally judged malicious to benign. GPT-5.5 Pro and Claude Opus 4.7 kept their verdict labels more often but still showed substantial severity downgrades and confidence reductions, and the attack also transferred to ELF binaries, where Gemini flipped 16 of 40. A verification-guided defense prompt roughly halves benign verdicts, but 42.9% of malicious samples are still classified as benign.

Contagion on the Trading Floor: How Adversarial Signals Spread in Multi-Agent Trading Systems

Qi Rong Sua, Junhao Dong, Nguyen Duc Thai, Yuqing Wen, Cheston Tan, Yew-Soon Ong Multi-agent trading systems built on large language models (LLMs) are appearing in quantitative finance, but little is known about how robust they are to adversarial inputs. The authors introduce the Generic Multi-Agent Trading System (GMATS) framework and a class of black-box attackers that use an LLM to write budget-constrained, plausibly benign social-media posts, which are injected into the analysts' evidence feed. Contagion metrics trace how this content propagates, measuring belief shifts at the analyst and coordinator layers and the change in backtest metrics between attacked and clean runs. On an offline benchmark of historical market and social data, even simple input-only attackers sharply reduce Sharpe ratios, while well-designed multi-agent topologies and coordinator prompts dampen the shocks under the same poisoning budget.

ClashBench: Conflicts Leading Agents to Seize and Harm

Yuejin Xie, Yu Li, Dadi Guo, Qingyu Liu, Yuqian Fu, Yanwei Fu et al. cross-listed When several AI agent sessions share an environment with a user's existing tasks, an agent with sufficient privileges may resolve a resource conflict by killing or disrupting the existing task instead of reporting the conflict. The authors call this failure mode destructive resource preemption. ClashBench contains 268 validated, executable conflict cases across 55 resource types and evaluates 17 models running inside Codex, Claude Code, and OpenCode. Agents destructively preempted the existing task in 44.5% of trajectories, and in 31.9% of those cases the final response mentioned neither the conflict nor the action taken. An instruction not to affect existing tasks reduced this behavior without eliminating it, while explicitly authorizing agents to stop local processes increased it.

Geopolitical Divisions Across Languages in Large Language Models

Maxim Chupilkin People increasingly ask chatbots about world events, which raises the question of whether the answers depend on the language of the question. The authors asked GPT, Claude, and Gemini to evaluate twenty statements about the war in Ukraine in 112 languages, collecting 67,200 responses. The balance between Russia-leaning and Ukraine-leaning answers varies by language, and when grouped by countries' official languages, more Russia-leaning answers go with more favourable public views of Russia, less support for Ukraine in United Nations votes, and less aid to Ukraine. The pattern appears in all three models, and the authors suggest that information warfare may shape the text these models are trained on and so spread geopolitical biases.

Governance-as-Code: Translating EU AI Act Technical Requirements into Executable Compliance Pipelines for Generative AI Systems

Rudrendu Kumar Paul, Sourav Nandy cross-listed Articles 8-15 of the EU AI Act were written for predictive AI and leave seven technical gaps when applied to generative systems, ranging from training-data provenance to generative fairness. Governance-as-Code (GaC) defines 43 machine-checkable acceptance criteria across six compliance modules. The checks run in a CI/CD pipeline, produce audit evidence indexed by article, and are implemented as published Rego policy code, which turns open-ended standards such as appropriate robustness into declared numeric thresholds and measures framing bias through counterfactual demographic probing. On two enterprise deployments, GaC reproduced every finding of a manual expert audit, including three violations that would trigger penalties, while cutting audit labor by about 75%.

Can Data Attribution Filter Out Subliminal Learning? Not Reliably

Moritz Weckbecker, Sweta Jena, Jonas M\"uller, Ponnurangam Kumaraguru, Sebastian Lapuschkin, Wojciech Samek et al. Subliminal learning lets language models pick up behavioral traits from training data that has no apparent semantic link to those traits, which defeats content-based filtering. The authors test whether gradient-based training data attribution can find and filter the responsible data. They compare GradCos, a contrastive GradCos variant, and EK-FAC across three models against divergence tokens, a strong baseline that requires access to counterfactual teacher models. When filtering individual tokens, EK-FAC removes a significant part of the effect while the other methods help little, filtering whole samples is weaker for every method, and success varies inconsistently across model and preference combinations.

Local Sparsity Enables Unsupervised LLM Safety Detection

Xin Chen, Gil Kur, Alexander Shevchenko, Andreas Krause Most deployment-time safety filters for large language models (LLMs) are trained with supervision on known unsafe data, so they can miss new attacks and harm categories. The authors instead treat safety as anomaly detection that models only safe inputs. They argue that under the linear representation hypothesis (LRH) this is statistically feasible, because nearby points in a sparse autoencoder (SAE) concept space share a small common set of active features, and they build a locally masked SAE-based anomaly detector on that idea, with theoretical backing and tests across several architectures on capability and safety datasets. When 1% out-of-distribution data is allowed for calibration, locally sparse methods reach near-optimal detection while computing with only 1-2% of SAE neurons.

Accuracy Is Not Enough: A Cross-Architecture Audit of Demographic Bias in Deep Knowledge Tracing

Dang Quang Minh, Nguyen Dung Son, Nguyen Huu Loi, Truong Viet Vu, Nguyen Thai Anh Deep knowledge tracing (DKT) models decide which students an adaptive learning system believes have mastered a skill, yet evidence on their fairness comes mostly from older Bayesian knowledge tracing. The authors audit four architectures (DKT, DKVMN, SAKT, AKT) under standard, reweighted and adversarial training on the Eedi and OULAD datasets. They measure bias with the ABROCA fairness metric, bootstrap confidence intervals and permutation tests. Every architecture shows significant socioeconomic bias on Eedi, and the most accurate model, AKT, is also the most biased, with ablation tying both its accuracy gain and its extra bias to its item-level Rasch embeddings; standard reweighting and adversarial debiasing left bias essentially unchanged whenever accuracy was preserved.

CleanVideo: Adaptive Concept Erasure for Text-to-Video Diffusion Models

Junchi Liao, Hongji Li, Wenrui Zhou, Lijie Hu cross-listed Concept erasure removes undesired visual content from pretrained generative models. In video, however, a target concept emerges gradually and varies across frames and denoising steps, so fixed interventions can miss it or introduce blur, jitter, and distortion. CleanVideo applies a low-dimensional subspace intervention controlled by a tri-modal gate, which reads spatiotemporal visual features, timestep signals, and text semantics to decide where, when, and whether to intervene, and it steers erased content toward natural surrogate concepts when one can be clearly defined. Across three video diffusion models it erases target concepts while preserving visual fidelity and temporal coherence, outperforming existing baselines on frame-level and video-level evaluations and under concept-recovery attacks when the protected pipeline is left intact.

Xeno-Interpretability: Investigating the Alien Minds of LLMs

F. Pierucci, M. Bracale Syrnikov, M. Prandi, M. Galisai, F. Giarrusso, P. Bisconti Interpretability research on large language models usually searches for human concepts such as truthfulness, refusal, or deception. The authors ask whether models also represent distinctions for which no human concept exists, which they call xeno-representations. They argue that the space of possible internal distinctions in an LLM is substantially larger than what finite human descriptions can cover, and they separate experimentally identifying a representation (locating, characterizing, and causally manipulating it) from interpreting its meaning. They sketch an empirical program for finding such representations and discuss implications for AI safety and multi-agent systems, where model-native representations could spread across interacting agents while remaining only partly visible in human-readable communication.

Stress-testing Alignment Midtraining

Sid Baines, Jonathan Bostock, Maria Angelica Martinez, Andrew Draganov, David Africa, Daniel Tan Alignment midtraining (AMT) continues pretraining on large volumes of alignment-relevant documents so that desired behaviors generalize beyond the post-training data, but there is little public evidence that it works. The authors test its assumptions on models of up to 110 billion parameters with up to 1 billion midtraining tokens. They find that midtraining can steer a model's motivation when post-training data is ambiguous between two motivations, but a tiny fraction of finetuning data suggesting a competing motivation erases the effect. In rule-following scenarios, rules were learned robustly only when demonstrations appeared in either the midtraining or the post-training data, and the authors conclude that current public evidence does not show midtraining can address the core difficulties of aligning powerful AI systems.

Fingerprinting Multimodal Large Language Models

Chao Huang, Meng Tong, Kejiang Chen cross-listed Multimodal large language models (MLLMs) are vulnerable to illicit deployment and unauthorized distillation, and existing provenance methods are confused by the language backbones many of these models share. The authors present the first study of multimodal model fingerprinting with two methods. AttnPrint is a white-box method that uses the low-frequency components of cross-modal attention distributions as fingerprints, and DistillTrace is a black-box method that applies hypothesis testing to model outputs to detect distillation. Across 154 model instances spanning 19 multimodal architectures, AttnPrint detects derivative models strongly while remaining robust to five downstream modification techniques, and DistillTrace provides evidence of distillation relationships under three parameter-independent techniques.

Inference-Engine Fingerprinting Attacks are Practical: Exploring Model-Driven Environmental Discovery, Exploitation, and Escape

Sarah Radway, Andrew Cheng, Vijay Janapa Reddi, James Mickens cross-listed Sandboxing discussions for AI inference stacks usually focus on network proxies or code execution environments, leaving the inference engine itself as an overlooked target for a misaligned model. The authors show that a model can fingerprint which engine is running it, such as vLLM or SGLang, and then use engine-specific exploits triggered solely by carefully chosen output tokens, with no malicious input required. They give concrete fingerprints for five popular engines, show how realistic agentic harnesses let a model identify its local engine, and describe a proof-of-concept exploit chain that reaches bare metal from a compromised engine. The paper closes with engine changes that would make fingerprinting harder.

Harm Laundering in GPT Models: Evidence That Gender Discrimination Is Transformed Rather Than Reduced Across Safety-Trained Generations

Sarah Wyer, Sue Black, Noura Al Moubayed Safety evaluations often rely on surface-level toxicity classifiers that show harm scores falling across model generations. Analyzing 450,000 gender-directed completions from 15 OpenAI models spanning GPT-2 to GPT-5, the authors argue discriminatory content is transformed rather than removed, a pattern they call harm laundering: sexual-violence clusters in women-directed output vanish by GPT-4, while men-directed completions gain positive themes that women-directed ones do not, and women-directed topic diversity falls 36% relative to men. Representational harm disparity measured by REGARD correlates with release date (ρ = +0.55) while Detoxify toxicity does not, so toxicity scores drop as representational harm grows. A three-criteria test and three-stage detection protocol for harm laundering are proposed for any generative model.

Quantifying Overclaiming Propensity in Frontier LLM Agents

Nolan Smyth, Yorguin-Jose Mantilla-Ramos, Pascal Jr Tikeng Notsawo, Saskia Helbling, Alberto Tosato, Mohamed Amine Merzouk et al. cross-listed An agent's final response is often the only account of its work a user sees, and the authors measure how often frontier coding agents overclaim, defined as a final response that contradicts information in the agent's own context, without any inference about intent. OverclaimBench combines five file-review scenarios, transcript-based coverage measurements, and registered planted defects, and is run on eight proprietary frontier models in their production command-line interfaces plus four open-weight models under a fixed harness. Agents failed to read all the files they were asked to review in 67.9% of runs, and among those incomplete runs they were misleading 80.4% of the time, either falsely claiming full coverage or omitting that coverage was incomplete. Requiring delegation to subagents raised reading coverage but left most incomplete reviews misleading, and agents that falsely claimed a complete review missed planted defects at about 1.8 times the rate of agents that read every file.
2 more specialized papers

Reinforcement Learning 20

Advantage Scale Calibration Imbalance in Group-Relative Optimization under Low-Variance Rewards: Diagnosis and Bounded Recovery

Fei Ding In reinforcement learning with verifiable rewards (RLVR), group-relative methods often treat the advantage scale as an implementation detail, which matters most when rewards within a group barely vary. The authors show that a single within-group scale denominator jointly sets reward-branch strength, prompt-level batch weight, and effective KL calibration. This explains why RLOO and Dr.GRPO let credible small reward gaps be dominated by the KL term, while GRPO's standard-deviation denominator can amplify tiny gaps without bound. They propose a Reward-Resolution Protocol that filters out sub-resolution jitter, plus MaxNorm-AC for bounded recovery of credible nonzero gaps, which improves over the strongest robust-scale baseline across dense and mixture-of-experts models on math and code reasoning.

Efficient Nash Equilibrium Computation for Cybersecurity Games

Michael Lanier, David Farmer, Yevgeniy Vorobeychik cross-listed Computing Nash equilibria for simulation-based cybersecurity games with policy-space response oracles (PSRO) is bottlenecked by payoff estimation, because every payoff-matrix entry requires Monte Carlo rollouts of a slow simulator. RWPS (Regret-Weighted Payoff Sampling) simulates only the cells the equilibrium is sensitive to and fills the rest with a surrogate trained on earlier simulated entries. It is supported by an instance-dependent error bound weighted by the opponent's equilibrium mixture, and by a coverage result showing that surrogate error cannot affect regret once the deviation-relevant cells are simulated. On three 21x21 games the refined bounds are four to six times tighter and correctly predict cost in advance (18% of the matrix for small-support games versus 82% for Colonel Blotto), and on the CyGym and ANSG cyber simulators RWPS reaches the lowest exploitability at the smallest budgets.

Improving Offline Goal-Conditioned Reinforcement Learning via Selective Reward Stimulation

Jing Zhang Offline goal-conditioned reinforcement learning struggles with sparse rewards and long horizons. The signal that a goal was reached arrives long after the early decisions that made it possible, and value-estimation error can drown it out. The authors analyze this as a reward-propagation problem and propose Reward Stimulation Implicit Q-Learning (RSIQL), which uses an auxiliary goal-conditioned value function to find intermediate states that make progress toward the goal and adds extra reward there, while keeping a single flat policy with no separate subgoal policy. On D4RL goal-reaching tasks and OGBench, it improves on goal-conditioned IQL on average and is competitive with hierarchical offline methods.

Reach or Solve? Attributing Agentic RL Gains with Checkpoint Handoffs

Xuan Liu, Jingbin Qian Reinforcement learning (RL) gains for multi-step language-model agents are usually read as better decision-making, but an agent's own actions shape the states it reaches later in an episode. Final success therefore mixes where the agent gets to with what it does once there, and comparing only states both policies reach can even flip the sign of the effect. The authors propose checkpoint handoff, which clones a state reached by one released checkpoint and hands it to another without retraining. This splits a gain into REACH, how often a policy arrives at a state a fixed number of actions from success, and SOLVE, how often it finishes from an identical cloned state. Across two benchmarks and two independently released training pipelines, the reacher-solver interaction is positive in all five conditions: a history produced by the RL policy is worth more to an RL solver than to a supervised fine-tuned one, and on ALFWorld RL improves both terms.

DeliveryGym: An RL Environment for Long-Horizon Embodied Agent Planning with Adaptive Curriculum

Haoqiang Kang, Yiming Zhang, Yiyang Guo, Chuying Li, Jianzhi Shen, Tianruo Rose Xu et al. Embodied LLM agents need to learn that finishing one task can use up the time, energy, or money needed for later work, which requires environments that preserve these dependencies across a whole trajectory. DeliveryGym is a 3D environment of continuous courier shifts that combines multimodal tool interaction with persistent world dynamics. It computes trajectory rewards from simulator events for reinforcement learning (RL) and adapts future training shifts to the policy's observed weaknesses while keeping evaluation fixed. Across six models and 13 city maps, agents reliably execute assigned deliveries but struggle to choose and sequence work over a shift; RL training raises Qwen3-VL-4B's net income by 54.3% on the fixed test suite, and the adaptive curriculum adds 16.5% over uniform sampling at the same rollout budget.

Steering Equilibrium Selection in Regularized Self-Play via the Reference Policy

Luis Leal Regularized self-play, the family of methods behind DeepNash's Stratego play, reaches a Nash equilibrium in two-player zero-sum games by best-responding to a slowly moving, entropy-regularized reference policy. When a game has many equally valued equilibria, a uniform reference silently selects the maximum-entropy one. On five exactly solvable games plus a 2-D polytope, the authors show that anchoring the reference at a chosen equilibrium and refining steers self-play to that equilibrium with mean coordinate error 0.007 at median exploitability of 5×10⁻⁵. They also report the limits: fixed off-manifold references cost 0.08–0.25 exploitability, boundary targets undershoot, and steering matters only against fixed, non-equilibrium opponents; they conclude that the KL anchor in RLHF-style training can be used to select an equilibrium, not only to keep training stable.

Dual-Axis Policy Optimization for LLM Agents: Bayesian Feedback Attribution and Trajectory Mass Normalization

Yingxuan Zhuang, Binhe Yu, Jingxiao Yang, Ruopei Sun, Ziting Li, Cheng Tan et al. Reinforcement learning for LLM agents involves two separate design choices: how environment feedback is used within a trajectory, and how complete trajectories are aggregated across a batch. BATON (Bayesian Attribution and Trajectory Objective Normalization) handles the first with Bayesian Feedback Attribution, which builds a feedback-conditioned posterior over sampled actions. It handles the second with Trajectory Mass Normalization (TMN), which gives every complete trajectory equal optimization mass. Applied with GRPO and GiGPO on ALFWorld, WebShop, and SearchQA, each axis yields its own gains and combining them performs best overall across model scales.

Graph-Based Stochastic Power-UCT: Monte-Carlo Graph Search with Power Mean Estimation

Tung Tran, Viet Bao Mai, Hoang Ta, Tuan Dam Monte-Carlo Tree Search (MCTS) creates a separate node each time the same state is reached by a different path, which wastes simulations in stochastic Markov decision processes (MDPs). GS-Power-UCT shares a node among states reached at the same planning depth while keeping separate values across depths, and it handles MDPs with cycles. It provably converges to the finite-horizon value at rate O(n^(-1/2)), the same rate as the tree-based Stochastic-Power-UCT, while reusing samples across shared states. Two variants share nodes across all depths, and one of them uses an adaptive horizon to converge to the optimal infinite-horizon value. Experiments on stochastic planning benchmarks show better sample efficiency than tree- and graph-based baselines.

EPIG-Tree: Compute-Optimal Branching for Gradient-Efficient Reinforcement Learning

Nikita Khomich, Leopold Hermansson, Ido Hakimi Reward-based reinforcement learning for language models, such as Group Relative Policy Optimization (GRPO), gives every token in a trajectory the same trajectory-level advantage, which explores and assigns credit inefficiently. EPIG-Tree treats building tree-shaped rollouts as a compute-allocation problem. It places new branches where they most reduce uncertainty about the policy gradient per unit of compute, and uses a variance decomposition to derive separate rules for adding new branches and for repeating suffix rollouts. It lowers gradient error in all nine dense continuous-control environments of a 13-environment sweep, and in single-turn math, tree-local credit beats flat GRPO, although branch placement matters less than token-level credit assignment; in multi-turn Wordle it reaches a final win rate of 0.850 versus 0.790 for flat GRPO, also overtaking entropy-based branching.

UnifiedPlayers: Enhance Tool-Integrated Reasoning in Agentic Reinforcement Learning

Wenjie Liao, Liangjie Zhao, Zehong Cao Self-evolving tool-using agents generate their own training data, but they usually judge it with static verifiers that cannot adapt to new failure modes, or with self-consistency signals that can reinforce errors shared across trajectories. UnifiedPlayers jointly trains three cooperating roles under GRPO with role-specific rewards: a Planning Player that generates tasks, an Execution Player that produces multi-turn trajectories with Python tool calls, and an Evaluation Player that builds executable verifiers. Across two model backbones and twelve benchmarks, it beats the strongest prior baseline by at least 3.5% on mathematical reasoning and 3.9% on general reasoning. The learned verifier reaches 84.2% adversarial detection accuracy, and its reward signal has 2.03 times the per-question variance of a self-consistency baseline, which makes its verifications more discriminative.

CARE-VI: Conservative Adaptive Reliability Estimation for Value Improvement in Off-Policy Actor-Critic Learning

Xiang Zou, Shengzhu Shi, Junqi Gao, Zhichang Guo Off-policy actor-critic methods depend on reliable temporal-difference targets, and refining those targets with alternative next-state actions can fail in three ways: noisy candidate rankings, biased reuse of selection scores, and fixed enhancement weights that amplify weak evidence. CARE-VI combines three matching components. Conservative Adaptive Ranking and Screening (CARS) keeps a budgeted prefix of ranked candidates and narrows it only when the evidence is clear; Selector-Evaluator Value Assessment (SEVA) ranks candidates with selector critics and reviews the chosen value with a separate evaluator critic; and Dynamic Adaptive Risk-aware Enhancement (DARE) scales each correction by candidate reliability and by how much the selector and evaluator disagree. The authors prove error bounds for each component, and when added to SAC, TD3, and TD7 on four MuJoCo tasks, the method achieves the highest mean return in all twelve settings.

Robust Federated Q-Learning with Almost No Communication

Sreejeet Maity, Aritra Mitra In federated reinforcement learning, many agents interact with a shared Markov Decision Process (MDP) and coordinate through a central server, but a small fraction of them may be adversarial and act arbitrarily. Robust Fed-Q combines model-based and model-free ideas with the median-of-means estimator from robust statistics to learn the optimal value function despite this corruption. The authors prove that it converges exactly to the optimal value function with infinite samples and achieves near-optimal finite-time rates that benefit from collaboration, while needing only a near-constant number of communication rounds (Õ(1)).

Improving Online Reinforcement Learning via Bidirectional Behavior Prior Distillation

Gong Gao, Xiao Lai, Jiaji Shen, Ning Jia, Xianhui Liu, Weidong Zhao Online reinforcement learning (RL) often has poor sample efficiency and unstable training because greedy policy updates amplify errors in the critic's value estimates. Existing behavior-prior methods try to constrain updates with behavior models pretrained on offline datasets, but the limited quality of those datasets caps how much they help. B2PD (Bidirectional Behavior Prior Distillation) instead uses action-value estimates to guide a conditional variational autoencoder (CVAE) toward generating a set of high-value behaviors, then distills these behavior priors into the agent, so knowledge flows in both directions between the generator and the policy. On state-based and pixel-based tasks, the method substantially improves sample efficiency while keeping policy optimization stable.

Improving Generalization and Robustness in Offline Reinforcement Learning via Boundary-Aware Data Augmentation

Gong Gao, Weidong Zhao, Xianhui Liu Offline reinforcement learning (ORL) algorithms tend to overfit their training data and generalize poorly. Regularization techniques borrowed from computer vision cope badly with how sensitive low-level physical signals are to distribution shift. The authors show that when training with random episode interpolation, the error bounds of the behavior policy and the action-value function grow with the distance between the interpolated states. Building on this, BADA (Boundary-Aware Data Augmentation) interpolates only within boundaries built from neighboring states, which produces synthetic data that better preserves the original distribution, and it attains state-of-the-art performance across diverse benchmarks with limited offline datasets.

Mitigating Retaliatory Algorithmic Collusion in Repeated Games

Karthik Sivachandran, Rohan Paleja Reinforcement learning agents maximizing their own reward in repeated games can converge to collusive, supra-competitive outcomes without communicating. The authors connect observed Q-learning collusion to the classical theory of Simple Penal Codes (SPCs), showing that any non-trivial SPC creates a detectable dependence in an agent's policy, measured as the total variation distance between its action distributions after cooperation versus defection histories. CURB (Collusion Unwinding via Reward shaping and Belief injection) penalizes this signal during Q-learning and is guaranteed to convert any SPC fixed point into a trivial one, ruling out collusive equilibria sustained by punishment threats. Empirically it substantially reduces collusion in Bertrand and Cournot repeated games and extends to deep Q-network agents in Bertrand competition.

RetireOPD: Self-Retiring On-Policy Distillation for Agentic Reinforcement Learning

Yan Yu, Zhengxi Lu, Yizhou Liu, Yichen Pan, Aozhe Wang, Qipeng Chen et al. Multi-turn agents trained with reinforcement learning (RL) get only one scalar reward per trajectory, and on-policy distillation (OPD) from a skill-conditioned self-teacher is meant to add dense token-level supervision, but the authors find that privileged information does not always make the teacher reliable and that its benefit depends on the training stage. RetireOPD first optimizes a decoupled, skill-conditioned teacher with environment rewards, then trains a skill-free student jointly with RL and OPD. With Adaptive Retirement, the student drops the teacher once their discrepancy stops shrinking and it reaches a target fraction of the teacher's success rate, after which training continues with RL alone. Across Qwen2.5 models from 1.5B to 7B, it improves ALFWorld success rate over the RL baseline by 14.1% to 18.8% and WebShop accuracy by 11.8% to 19.0%, surpassing its own teacher in every setting.

Score Centering Stabilizes Off-policy Reinforcement Learning

Martin Marek, Max Ryabinin Reinforcement learning of large language models is sensitive to small differences between training and inference engines, known as the training-inference mismatch (TIM), and removing it entirely would cost too much rollout efficiency. The authors argue the instability comes mainly from drift, a persistent bias between the two engines that accumulates with every training step, and derive an additive score centering correction term that cancels it. On models from 0.6B to 30B parameters, score centering alone matches or outperforms importance-sampling methods under quantization, with the gap widening as the mismatch becomes more severe. Because the correction is additive it also composes with importance sampling, and the combination beats pure importance-sampling baselines in staleness experiments.
3 more specialized papers

Multimodal 17

To Memories and Beyond: From Remembering to Knowing You across Long-Term Multimodal Personal Archives

Wenqi Zhou, Zhuorui Yu, Kaiao Wen, Hao Zheng, Xinyi Zheng, Peiran Wu et al. Existing long-term memory benchmarks for AI assistants are mostly synthetic and text-only, which confines them to shallow factual recall. ReaLMem (Real-world Long-term Multimodal Memory) is built from authentic multi-year personal visual archives with first-person annotations and tests models on three tiers: factual recall, persona inference, and predictive personalization. The authors also propose ChronoProfiler, which scores how stable each user attribute is over time and uses that score as a salience prior to resolve conflicting preferences and combine several active ones. Evaluations of frontier multimodal large language models (MLLMs) and memory systems find that predictive personalization is a consistent ceiling, and that temporally informed representations substantially improve personalization.

Less Is More: Graph-free Multimodal RAG via Multi-signal Late Fusion

Tithi Rakshit, Hongkuan Zhou, Lavdim Halilaj, Yuqicheng Zhu Graph-based retrieval-augmented generation (RAG) for multimodal, cross-document question answering is costly to build, slow to query, and hard to maintain. TrioRAG drops the graph and retrieves with three independent signals over a shared multi-vector index of page text and images: the question, the anchor image, and a query that a vision-language model writes from both. It then merges the results by late fusion. Across three benchmarks it matches or beats graph-based systems while running 1.6-2.3x faster per query at lower total cost. The authors also release AutoQA, a model-curated automotive benchmark built on noisy web images, where image retrieval reaches only 19.3% document-level recall and the text-derived signals keep retrieval robust.

From Models to Systems: A Comprehensive Survey of Efficient Multimodal Learning

Pan Wang, Siwei Song, Hui Ji, Siqi Cao, Heng Yu, Zhijian Liu et al. cross-listed Multimodal models face mounting compute, memory, and deployment bottlenecks, and research on Efficient Multimodal Learning (EML) remains fragmented. The authors organize over 300 works into a three-level taxonomy of model, algorithm, and system, covering architectural parsimony, execution refinement, and hardware-aware orchestration. They also analyze how co-design across these layers shapes the trade-off between efficiency, utility, and privacy. A case study of Multimodal Large Language Models (MLLMs) traces the field from structural tweaks to full-stack resource orchestration, followed by domain-specific optimization blueprints and open challenges.

Full-Duplex Speech Models Take the Floor When Asked, Not When Needed

Linkai Peng, Baorian Nuchged, Kaiqi Fu, Yuyang Yao Full-duplex speech models can listen and speak at the same time, but it is unclear whether they know when to speak up uninvited, as a person would to correct a false claim or warn of danger. The authors build context-matched English monologues in which only a trigger utterance changes, define 10 conditions from turn-taking rules, and shorten pauses so silence creates fewer openings to speak. Across five model families, being addressed and silence are far more reliable triggers than false facts or hazards. Even when they do take the turn, Moshi and PersonaPlex challenge the false claim in only 14 to 15% of non-empty replies and warn of danger in just 4 to 7% of hazard replies, a gap in both when the models speak and what they say.

Uni-LaDiR: Latent Diffusion Unifies Multimodal Reasoning

Haoqiang Kang, Yizhe Zhang, Nikki Lijing Kuang, Yian Ma, Lianhui Qin Multimodal reasoning models often concatenate modality-specific thought tokens in one sequence, leaving the model to bridge the differences between representations as it reasons. Uni-LaDiR (Unified Latent Diffusion Reasoner) uses a unified encoder to map teacher reasoning steps from different modalities into shared latent thought tokens. Because more than one next step can be valid from the same context, a diffusion model predicts each next block of thought tokens from the input and the preceding blocks, and the encoder and reasoner share weights and are trained jointly. Across eleven vision-language model (VLM) benchmarks and two vision-language-action (VLA) suites, it reports relative gains of 7.3% on visual reasoning and 6.1% on robot manipulation over the strongest evaluated baselines.

AVTrace: Diagnosing Audio-Visual Temporal Reasoning in Omni Models

Longyin Zhang, Parth Sakhare Mahendra, Chengwei Wei, Ning Zhang, Lim Ming Chong, Sirui He et al. cross-listed Omni models can describe videos, but it is unclear whether they can locate events in time, keep events in order, or judge whether audio and video are in sync. AVTrace is a silver-standard diagnostic suite covering onset and span grounding, synchronization, next-step prediction, cross-modal localization, chain parsing, and event-conditioned comprehension, with 34,114 training examples and balanced development and test splits of 3,500 and 7,000 examples. All five open omni models tested score below the 0.556 majority-label baseline on synchronization verification and do poorly on chain parsing and event-conditioned tasks, while parameter-efficient temporal post-training improves Gemma4-E4B-it on several metrics. The authors conclude that overlap with semantic reference text should not be used as a proxy for temporal localization.

Cross-Modal Attention Acts as a Frequency Filter: Why Verbose Prompts Improve Robustness in Vision-Language Models

Farooq Ahmad Wani, Maria Sofia Bucarelli, Mujtaba Hussain Mirza, Oleksandr Pryymak, Aryo Pradipta Gema, Iacopo Masi et al. cross-listed Vision-language models (VLMs) break down under image corruption, and the wording of the question pushes robustness in opposite directions. Verbose phrasings such as adding 'Please look carefully and answer' make models more robust, while fine-grained or semantically complex questions make them more fragile. The authors trace both effects to question-conditioned cross-modal attention acting as a spectral filter over image patches: verbose questions broaden its frequency support, fine-grained ones narrow it to fewer visual scales, and answers drift most when the filter and the corruption overlap in spatial frequency. Tests on Qwen3-VL and LLaVA-OneVision across GQA and CLEVR show that verbose paraphrasing cuts answer-drift variance by 70-81% on the 8B models, and simply padding the prompt gives measurable accuracy gains even under corruption.

Lens: Bringing the Right Semantic Perspective into Focus for Training-Free Multimodal Representation Learning

Xinran Liu, Shouqian Shi, Yixian Chen, Ruizhi Chen, Xin-Wei Yao, Sheng Zhong Multimodal large language models can act as training-free embedding models, but current prompting methods for extracting representations often yield vectors dominated by the most salient input content rather than the perspective the downstream task requires, a problem the authors call semantic perspective misalignment. Lens addresses this in two steps: Semantic Perspective Anchoring ties the task-required perspective to a task-specific readout phrase, and Contextualized Phrase Readout places that phrase after the complete input and aggregates its token states. It needs no parameter updates, architectural changes, or reranking. Across all 36 MMEB datasets it reaches an overall Precision@1 of 63.9, 10.2 points above the closest same-backbone training-free embedding baseline.
9 more specialized papers

Vision 15

Astronex-World 1.0: Real-Time Interactive World Model Foundation

Xin Zhou, Cong Miao cross-listed Astronex-World 1.0 is an open video world model. Given a text prompt or an initial image, it predicts future frames conditioned on camera trajectories, continuous actions, an embodiment identifier, and text events inserted partway through a rollout. Built on the Wan2.2-TI2V-5B prior, it comes in a bidirectional version and a block-causal version with key-value caching across blocks, trained in five stages that cover camera and action control, conversion to causal generation, few-step distillation, and DMD/DMD2 distribution matching. All training runs on two NVIDIA L20 48 GB GPUs, and the causal model streams 832x480 video at 24 fps in real time on one; it scores 73.5 on WBench Navi and 70.0 on WBench Full, beating the larger LongCat-Video (13.6B) and Helios (14B) and landing within a point of the 22B LTX-2.3.

TouchSight: Bare-Handed Tactile Prediction from Egocentric Video via Generative Visual Augmentation

Danyan Zhou, Jinxuan Lu, Jiawei Lin, Tianxing Chen, Chuqiao Lyu, Wenbo Ding cross-listed Tactile signals give direct contact and force information for dexterous robot manipulation, but collecting them requires intrusive and costly instrumentation. TouchSight predicts dense contact forces across the whole hand from monocular egocentric video. It is trained on 500 hours of pressure-glove recordings plus hand-object interaction data, and the authors bridge the gap between gloved and bare hands with TwinTouch-20H: 20 hours of gloved recordings that generative video models re-render as bare hands on new backgrounds while keeping the measured tactile labels. The model outperforms prior contact-prediction methods on OakInk2, qualitatively generalizes to unseen bare-hand videos, and improves as glove supervision scales, which the authors take to show that dense tactile signals can be recovered from egocentric vision alone.

Video DeltaNet: A Video-Native Hybrid Attention for Livestream Video Generation

Haocheng Xi, Yiming Xie, Hexu Zhao, Yiwen Zhang, Michael Liu, Thomas Creavin et al. Attention over long spatiotemporal token sequences is the main compute bottleneck in video diffusion models, and naive linear attention loses the fine-grained interactions needed for quality. Video DeltaNet (VDN) combines local softmax attention with a bidirectional linear memory whose Video Delta Attention updates once per frame using all of that frame's spatial tokens, with separate output projections, learnable gates, and a staged teacher-alignment recipe for retrofitting pretrained models. Instantiated on MiniMax H3 with eight-step distillation and an optimized SGLang serving stack, it denoises a 14.3-second 768p video in 6.70 seconds on eight NVIDIA B200 GPUs, a 14.5x speedup over the 50-step dense baseline.
12 more specialized papers

Reasoning 11

Reflective Recovery: A Self-Supervised Method for Reasoning by Learning from Mistakes

Qirui Chen, Renjie Pi, Jiahui Gao, Lingpeng Kong Fine-tuning large language models (LLMs) only on correct reasoning traces hits what the authors call a Scaling Collapse, where adding more positive examples for a limited problem set stops helping, and such models struggle to recover once an intermediate step goes wrong. Reflective Recovery turns failed attempts into training data: it takes the initial segments of incorrect trajectories, appends them to the prompt, and guides the model to a valid solution from there, teaching error recognition and correction without external critics or reward models. On DeepSeek-R1-Distill-Qwen-7B it raises accuracy from 30.0% to 37.5% on AIME 2025 and from 37.6% to 47.8% on Minerva. The authors' analyses indicate that it breaks through the scaling-collapse plateau and produces emergent self-correction behavior.

What Do Current Systematic Generalization Tasks Miss? A Reasoning-Centered Analysis

Chengwen Qi, Deheng Ye, Yatao Bian Systematic generalization, meaning solving new problems by recombining known parts, is usually tested with simplifications: actions that combine almost linearly, tests that only use longer inputs, and goals that spell out the required actions. TranSGrid is a testbed that requires deductive, inductive, and abductive reasoning in a single task. Across seven Transformers, the largest model solves 79.6% of a held-out test set but only 55.3% of TranSGrid and 15.8% of its hardest subset, and the gap remains even at lengths seen in training. Adding back either near-linear action composition or goals that spell out actions brings solve rates back to roughly held-out levels, which suggests existing tasks drop the inductive or abductive demands.

Compositional Reasoning in Language Models under Reinforcement Learning Post-Training

Yu He, Yingxi Li, Yifei Wang, Ellen Vitercik Reinforcement learning (RL) post-training has improved language model reasoning, but its effect on compositional reasoning, meaning the combination of learned skills in new ways, is less understood. The authors formalize compositionality with a dependency-graph framework that defines three levels of increasing complexity, and test it on data-structure tasks with deterministic rewards. They find a consistent asymmetry: training on separate skills does not reliably transfer to tasks that combine them, while training on combined tasks transfers back to the separate skills, and they give a theoretical explanation. A pilot study on real tool-calling benchmarks gives preliminary evidence that the asymmetry carries over to practical settings.

LLM-as-an-Improver: Turning Verification into Better Candidates

Akiyoshi Tomihari, Yuma Ichikawa Verifier-based selection samples several candidate solutions and uses a verifier to pick the best one, but it discards the verifier's feedback once ranking is done. Verify-Repair-Reselect (VRR) reuses that feedback to build better candidates. It keeps the initial winner and conditionally adds repaired versions of the winner and runner-up plus a solution that takes a new approach, filters out invalid or duplicate candidates using only inference-time information, and then reselects under the original criteria. Across several models on code-generation and reasoning benchmarks, VRR improves on fixed-pool selection in many settings and can recover correct solutions even when every candidate in the initial pool is wrong.

Chain-of-Thought Entropy as a Reliability Signal: A Preregistered Reproduction

Theodore O. Cochran The authors run a preregistered reproduction of a 2026 result by Zhao: the shape of an LLM's chain-of-thought entropy trajectory predicts whether the answer is correct, but the size of the total entropy drop does not. Using the full GSM8K and MATH-500 test sets and four open-weight models, including a reasoning-distilled one, they find that the shape signal replicates. On the anchor model, chains whose entropy falls steadily are 9.6 percentage points more accurate on GSM8K and 27.5 points more accurate on MATH-500. The magnitude signal depends on the setting, correlating near zero with correctness on GSM8K but at +0.414 on MATH-500, and in an exploratory comparison the entropy of the final step alone beats the binary shape flag by ROC area in all eight model-benchmark combinations.

When2Think: Learning Difficulty-Aware Length Control for Efficient Hybrid Reasoning Models

Jaejun Shim, HyunJin Kim, Young Jin Kim, JinYeong Bak Large Reasoning Models (LRMs) tend to overthink easy problems and underthink hard ones, and uniform length penalties or rigid routing save compute on easy cases at the cost of accuracy on hard ones. When2Think is a post-training framework for hybrid reasoning models that learns when to answer directly (NoThink) and when to reason at length (Think). Its core is Instance-level Difficulty-Aware Control (IDAC), a reward-shaping scheme based on pre-computed per-problem accuracy and token-usage statistics, which is combined with verifier rewards and batch-standardized advantages for stable critic-free optimization. On AIME24, Pass@3 rises by 10.0% while token usage falls by 27.9% relative to the base model, and on AIME25 it reaches 40.0% Pass@3, beating compression and routing-only baselines.

Learn Your Own Thoughts: Abstract Token Curriculum

Khashayar Gatmiry, Avrajit Ghosh, Parsa Mirtaheri, Jason D. Lee, Nika Haghtalab, Emmanuel Abbe et al. Chain-of-thought (CoT) reasoning needs explicit supervision on thinking tokens, which demands rich task-specific data. Abstract Token Curriculum (ATC) trains a model on a sequence of progressively harder problem distributions so that it develops continuous internal thoughts without direct supervision or hand-designed scratchpads. Theoretically, the authors show that when single-layer softmax attention learns parity functions under ATC, attention naturally focuses on the context tokens that offer the easiest path to predicting the next token. Experimentally, ATC is effective on graph reachability and arithmetic tasks and shows advantages over prior methods for training continuous thoughts.

PetriBench: Benchmarking LLM Reasoning over Dynamic State Spaces

Pyrros Koussios, Benjamin J\"ager, John Hua Yao, Ajay Sridhar, Violet Xiang, Chenhao Li Many large language model (LLM) reasoning benchmarks test a single skill, depend on outside knowledge, or are expensive to extend. PetriBench uses Petri nets, an established formalism for modeling concurrent and distributed systems, to generate self-contained tasks in four families at Easy, Medium, and Hard levels, each checked against an exact ground truth. Across proprietary and open-weight models, accuracy falls consistently with difficulty, and harder instances reveal increasingly distinct task-specific capability profiles. Additional test-time compute helps, but its effect differs by task type, and procedurally generated instances scale smoothly with structural complexity.

What Does Privileged Information Add to On-Policy Self-Distillation?

XiuYu Zhang, Wei Chow, Junfeng Fang, Zhenkai Liang, Tat-Seng Chua On-policy self-distillation (OPSD) trains a language model against a frozen copy of itself that is shown an answer or worked solution, and the question here is how much that privileged information adds beyond distillation alone. The authors build AMPLE-Math, 5,319 math problems each with six reasoning views sharing one answer, and compare every view against matched reference-free distillation. With a thinking-enabled teacher supervising direct-response rollouts, reference-free distillation accounts for much of Qwen3-1.7B's improvement, the extra benefit from references is modest, and complete traces add about two percentage points for SmolLM3-3B. Switching the student to long thinking-enabled rollouts turns the gains into losses in both model families, suggesting OPSD mainly improves access to existing reasoning ability through parameters shared across inference modes.
2 more specialized papers