Research

New AI papers from arXiv, picked daily and explained with their claims, benchmark results and code.

2566 articles · page 23 of 54 · The Research front page

Theory

Training spikes in language models replicated by simple quadratic models with heavy-tailed data

The authors introduce Power-Law Random Feature (PLRF) models—simple quadratic models with heavy-tailed, power-law distributed inputs—that exhibit the same intermittent training spikes seen in large language model (LLM) pre-training. They develop a layer-wise simulation algorithm that predicts when spikes will occur in deep neural networks, and in a case study on a Transformer trained with Adam, they derive a beta2 hyperparameter schedule that avoids spikes and improves performance.

Agents

Alternating AI agents across sessions beats single agents on machine learning tasks

The authors identify two failure modes in long-horizon machine learning agents: long-horizon deceleration, where reasoning intensity drops as a session stretches, and harness staleness, where custom tooling helps less as base models improve. Their workflow, Humanize MLE Agents (HMA), alternates two agents on a shared workspace with context resets. On 75 Kaggle tasks in MLE-bench it reached a 78.2% any-medal rate, 8.0 points above the strongest open-source baseline.

Language models

Branching student trajectories improves on-policy distillation efficiency and accuracy

The authors propose BranchOPD, an on-policy distillation method that selects informative fork points using student uncertainty and teacher-student disagreement, then resamples student continuations from shared prefixes. Across mathematics and agent benchmarks, BranchOPD outperforms vanilla OPD and seven-rollout OPD while generating roughly 19% fewer student tokens on ALFWorld and 31% fewer on WebShop.

Evaluation & benchmarks

Coding agents rarely build the agent a user actually asked for.

The authors introduce AgentSWE, a benchmark for agent software engineering in which coding agents are commissioned to build, edit, or optimize a complete agent from a natural-language requirement. Across 25 tasks, they evaluate five models in the Codex harness plus other pairings, grading frozen submissions against requirement-derived rubrics on held-out cases. The strongest builders average 19.1 on creation and 31.6 on editing, and none closes more than 5 percent of the remaining gap in optimization.

Efficiency & systems

Two-rate precision allocation cuts MoE memory footprint and decode traffic

The authors identify a store-read gap in Mixture-of-Experts (MoE) models, where a fixed-precision checkpoint stores weights at one rate but decode reads them at a much higher rate (2.95× for BitsMoE). They propose DuoRate, which stores one uniform tier of a prefix-readable weight stream offline and then, for each workload, selects per-expert read tiers via a Lagrangian rate-distortion optimization that cancels routing frequency. On Qwen3-30B-A3B, DuoRate reading 2.3 bpw outperforms every 2-bit-class baseline by 6.3–47.0 average accuracy points, and at 2.9 bpw it matches 4-bit formats that read 1.4–1.6 more bpw.

AI for science & health

Natural language can steer all-atom protein design across diverse objectives

Lee and colleagues developed Prompteina, a model that jointly generates protein sequences and all-atom structures conditioned on natural-language descriptions of desired properties. Across structural-control and binder-design benchmarks, it generally outperformed models requiring specialized input formats, and nine of 89 experimentally tested designs bound a previously unaddressed target.

Reinforcement learning

Intervening During Rollouts Helps Agents Learn Beyond Their Initial Limits

Chen and colleagues introduce Rollout-Time Intervention (RTI), a reinforcement-learning method that turns selected failed agent rollouts into successful training trajectories using evaluation rubrics. Across five benchmarks and two model backbones, the authors report that RTI outperforms standard reinforcement-learning baselines and eventually increases unaided task success, rather than merely improving performance through intervention at test time.

Vision

Long skip connections help diffusion transformers learn cleaner visual representations

Meng and colleagues investigate why Diffusion Transformers, or DiTs, can generate strong images while producing weaker visual representations than U-Net diffusion models. They report that adding long skip connections improves the quality of intermediate activations used for vision tasks, and propose that these connections let diffusion noise bypass the representation-forming core of the network.

Agents

Multi-agent adversarial review boosts LLM-based SOC alert triage accuracy

The authors studied five representative LLM-based agent approaches for tier-1 SOC alert triage and found that all missed at least 40.4% of attack-related alerts. They then designed AIDA, a multi-agent framework that requires an explicit proposed decision, independent challenge, and stronger evidentiary requirements before dismissal, achieving an F1 score of 0.958 (compared to 0.371–0.744 for baselines) and reducing the false-negative rate to 3.1%.

Agents

Autonomous agent uses identifiability analysis to decide why a model plateau has been reached

The authors introduce LLM-IDEA, an agent that couples a large language model proposer with a deterministic identifiability engine to triage plateaus in mechanistic world model learning. The engine computes the sensitivity matrix rank and certified exhaustion, enabling a three-way verdict: capability limit, resolvable within design class, or certified exhausted. On the Alien Universe testbed, LLM-IDEA under an identifiable protocol reached discovery depth at least three on 8/8 seeds versus 1/8 without the identifiability engine.

Robotics & embodied AI

Large-scale benchmark and end-to-end model achieve robust dexterous grasping in cluttered scenes

The authors introduce OmniDex, a massive simulation benchmark for dexterous grasping in cluttered scenes, created via a scalable seed-and-filter strategy that avoids costly scene-level optimization. They also propose an end-to-end grasping model that uses Soft Winner-Takes-All learning and human-inspired physical constraints, achieving state-of-the-art performance on the benchmark without the latency of post-optimization.

Speech & audio

Unified model blends general audio understanding with spatial awareness

The authors present MiDashengLM-Spatial, the first open-source end-to-end audio-language model that jointly handles general audio understanding and spatial awareness. By augmenting an existing monaural LALM (MiDashengLM) with a spatial encoder (Spatial-Dasheng) via a hierarchical conditioning module, the model achieves superior performance on spatial reasoning benchmarks while remaining competitive on standard monaural audio tasks.

Generative media

Single-pass GAN matches diffusion quality for real-time talking heads at 43 ms latency

Authors from Meta Reality Labs present FaceGAN, a single-pass GAN for audio-driven facial animation that runs at 43 ms latency and 12x real-time on one GPU. They identify that a causal generator driven by i.i.d. noise cannot produce smooth motion without collapsing innovation variance, and introduce acausal noise shaping to dissolve this limitation without adding audio latency. FaceGAN matches or surpasses diffusion models in fidelity while avoiding their iterative sampling cost.

Evaluation & benchmarks

New benchmark tests AI judges on long computer-use tasks by swapping instructions

The authors introduce AgentHorizon, a benchmark of 1,373 instruction-trajectory pairs built from 166 hours of human-recorded computer-use sessions across three operating systems. By swapping instructions between closely related tasks, they create negative examples that test whether an AI judge can spot subtle failures in trajectories that look complete. Evaluating eleven judge models, they find that the best, GPT-5.5, achieves 80.9% balanced accuracy on the hardest split, and that providing tools helps some models but hurts others.

Safety & security

Distillation can expose hidden behavior or retain safer capabilities

Prasanna, Tay and Westover test two ways to use model distillation, in which a weaker student learns from a stronger teacher, as an AI safety tool. In controlled model organisms, distillation made secret-keeping models more willing to disclose hidden behavior, while modified training procedures transferred mathematical capabilities with substantially less transfer of a proxy for misalignment. The work supports each strategy separately, not the broader claim that one must always succeed.

Generative media

Distribution matching distillation and drifting models are equivalent under finite-sample analysis

The authors prove an exact finite-sample correspondence between Distribution Matching Distillation (DMD) and Drifting Models, two approaches for one-step generative modeling. By converting the velocity-field from pretrained diffusion models into attraction force fields and estimating repulsion from the generative distribution, they show that DMD's optimization is equivalent to drifting model training. They then introduce Multi-Bandwidth DMD (MBDMD), which improves convergence and generation quality on image datasets.

Evaluation & benchmarks

LLMs match human annotators on some MT quality tasks, but both remain unreliable

The authors evaluated four LLMs as annotators for two machine translation quality schemes, MQM and ESA, comparing their agreement with human annotators across a 70-language-pair test set and WMT23/WMT25 data. LLM-human agreement matched or exceeded human-human agreement for some tasks, but both varied widely across annotation schemes, language pairs and domains, and remained unreliable for most settings.

Safety & security

Null-space activation steering enables training-free LLM unlearning without utility loss

The authors propose Nullify, a training-free, non-destructive method for LLM unlearning that operates entirely in activation space during inference. It achieves forget quality comparable to or better than existing gradient-based and preference-optimization methods on the TOFU and MUSE benchmarks while keeping utility near-lossless, all at a small fraction of their compute and memory requirements.

Efficiency & systems

Lower reconstruction loss can degrade quantized LLM performance; robust refinement fixes it

The authors show that minimizing reconstruction loss on calibration data during weight-only post-training quantization (PTQ) can hurt model performance, even on the very same data. To address this, they propose Distributionally Robust Quantization (DRQ), a post-hoc refinement that minimizes worst-case reconstruction loss over a constrained set of input activation distributions, and demonstrate gains across six representative PTQ methods on dense and mixture-of-experts LLMs.

Vision

Generative and agentic pipeline reconstructs scene-aligned 3D objects from casual photos

GATOR reconstructs complete, textured 3D objects and their scene-relative pose from one or a few casual images. The authors combine a generative cascade with agentic refinement: the cascade produces an initial asset, which anchors a multimodal agent that edits geometry and texture against the input observations. Results show strong fidelity on synthetic objects, cluttered tabletops, and indoor scenes.

Evaluation & benchmarks

Benchmark and agent for verifying images against real-world facts

Chen et al. introduce WorldFact-Bench, a dataset of 1,274 real–fake image pairs spanning ten domains, each containing a factual conflict while preserving visual plausibility. They also propose PERSIST-Agent, an iterative verification system that maintains a persistent state linking candidate facts, observations, evidence, and verification statuses. On 8B backbone models, the agent raises pair accuracy by up to 10.4 percentage points over direct judgment, but overall performance remains modest, highlighting the gap between visual plausibility and factual correctness.

Evaluation & benchmarks

Benchmark of 82 unresolved problems in theoretical sciences tests AI beyond known results

The authors introduce OpenProblemBench, a benchmark of 82 open problems drawn from the mathematics and theoretical physics literature. Each problem supplies research context, assumptions, and prior progress. Four evaluator models independently assess submissions for correctness and progress without reference solutions. Across seven evaluated configurations, GPT-6-Astra attains a mean judged solve rate of 14.0%, compared to 2.4–6.7% for other models.

Evaluation & benchmarks

Clinical AI benchmarks poorly reflect how clinicians actually use language models

Vishwanath and colleagues compared eight months of real-world use of an institutional language model assistant with 58 public clinical AI benchmarks. They found a substantial mismatch: clinicians mostly requested help with documentation, administration and knowledge retrieval, while benchmarks emphasized diagnosis and assumed questions could be answered from the information provided.

Evaluation & benchmarks

LLM-assisted peer review should prioritize error detection over imitation of human reviews

The authors introduce a verification-centric perspective for LLM-assisted peer review, focusing on error detection rather than mimicking human reviews. They present a scalable benchmark built by synthetically inserting logical contradictions into conference papers, and propose a Multi-Layered Review (MLR) framework that conducts multiple passes over the manuscript before generating feedback. Across evaluations, MLR shows strong alignment with human review scores, achieves high error detection performance, and offers complementary reviewer focus, though it remains vulnerable to adversarial manipulation.

Generative media

Decomposing video editing into keyframe editing and motion-guided interpolation

The authors propose AVE, which first edits a sparse set of keyframes using a strong image editor, then generates the full video via motion-guided image-to-video diffusion, treating edited keyframes as anchors. On IVEBench and VIE-Bench, AVE achieves state-of-the-art performance in instruction following, temporal consistency, and content fidelity, with the quality strongly tied to the image editor used.

Language models

Raw video alone, with no captions, can mid-train language models for better vision.

The authors test whether a pretrained language model can improve its visual understanding by mid-training on raw video frames with no captions or text loss. They encode frames as continuous visual tokens and train the model to predict the next visual token, then apply identical instruction tuning to this model and a baseline. The mid-trained model outperforms the baseline on video and image benchmarks while matching text performance.

Language models

Composed matrix normalizations unify Muon optimizers and cut pretraining token use

The authors unify recent Muon optimizer variants as chained linear minimization oracles (LMOs), compositions of norm-ball projection steps such as the matrix sign. They show that many practical chains lack standard LMO guarantees and can diverge on convex objectives, yet in linear associative memory chaining provides a provable learning advantage. Their proposed TensorChain optimizer stacks compatible weight matrices across layers into a 3D tensor and normalizes across axes, achieving 9.6% average token savings over Muon at matched validation loss in Qwen3 0.6B and 1.7B pretraining.

Reinforcement learning

Separating visual and language reasoning phases improves vision-language model accuracy

The authors propose SPLIT-RL, a staged reinforcement learning method that trains a vision-language model's visual reasoning (VR) and language reasoning (LR) capabilities in separate phases. By using the VR output as a bottleneck and applying claim-level advantage computation, they achieve accuracy gains of 1.4 to 6.1 points over standard GRPO across five model families, while also improving both VR and LR individually.

Agents

Diffusion language models enable faster plan generation and repair for long-horizon agents

The authors introduce Plan-and-Patch, a framework that uses a diffusion language model (dLLM) to generate structured plans and repair them by infilling affected regions while preserving surrounding steps. On Natural Plan benchmark without task-specific training, the diffusion planner achieved 53.7% repair success versus 27.0% for autoregressive planners, and after task-specific training on ALFWorld and TextCraft, diffusion reduced plan-generation latency by 39-46% while maintaining similar success.