Research

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

2566 articles · page 12 of 54 · The Research front page

Language models

Gold-conditioned teacher softens targets for language model fine-tuning

The authors propose Gold-Conditioned Distillation (GCD), a self-distillation method for supervised fine-tuning of large language models. By using the same model as both teacher (conditioned on the gold response) and student (conditioned on the prompt only) and training via forward KL divergence on gold tokens, GCD achieves better accuracy on new tasks compared to standard supervised fine-tuning, while generally reducing performance degradation on general benchmarks.

AI for science & health

Probabilistic AI forecasts retain skill for record-breaking weather extremes

Van Velthoven et al. evaluate four probabilistic AI weather models against the physics-based IFS-ENS ensemble for forecasting record-breaking temperatures and wind over land in 2022. The authors find that AI models outperform IFS-ENS for heat and cold records at nearly all lead times and record depths, with the advantage strengthening for deeper heat records. However, all systems show reduced skill for wind and as lead time increases.

Generative media

Noise-rejuvenated SMC enables test-time scaling for flow matching image generation

The authors introduce noise-rejuvenated sequential Monte Carlo (SMC), an inference-time scaling method for text-to-image flow matching models. By perturbing resampled particles via source noise replacement, the method enables exploration without converting the deterministic ODE sampler to an SDE. Experiments on three state-of-the-art models show consistent improvements in reward-guided generation across multiple benchmarks.

Efficiency & systems

Per-layer KV-cache budgets learned via multi-objective search improve LLM inference efficiency

The authors introduce MOSAIC, a multi-objective search method that learns per-layer key-value cache budgets for LLM inference. On two models and four eviction methods, MOSAIC beats uniform allocation in 146 of 154 (task, method, budget) settings, achieving gains of up to +48 points on RULER and +11.9 on LongBench. It reaches the same score as uniform allocation with up to 4x less cache.

Generative media

Geometry-aware test-time scaling improves camera control in video diffusion without retraining

The authors present GeoART, a training-free self-refinement method for camera-conditioned video diffusion. By generating multiple candidates at selected denoising steps and evaluating them with a geometry prior, GeoART improves camera controllability and multi-view consistency without modifying the pretrained model. Rank-calibrated probabilistic selection, rather than greedy choice, balances score magnitude and relative rank to handle noisy geometry scores.

Generative media

BEV maps enable human-friendly control for embodied navigation video generation

The authors introduce Map2Vid, a task that generates egocentric navigation videos conditioned on bird's-eye-view (BEV) maps, offering a more intuitive alternative to text prompts or camera trajectories. They built a dataset of 117,800 navigation sequences across 61 indoor scenes, each paired with videos, BEV maps, trajectories, and language instructions. A curriculum training strategy gradually weakens non-map inputs, achieving robust performance with BEV maps alone.

Language models

New preference optimization curbs LLMs' wasteful thought switching, cuts tokens by 63%

The authors propose SteadyThought (ST), a thought-level preference optimization framework to address 'under-thinking' in large reasoning models, where models frequently switch reasoning paths even when a promising path is found. ST identifies switching points using linguistic and entropy signals, generates single-path continuations as preferred responses, and applies preference optimization to discourage unnecessary switching. The key finding: ST reduces token consumption by up to 63.8% while maintaining strong reasoning accuracy across multiple benchmarks.

Vision

Vision-language alignment fails to improve text-only spatial reasoning

Singh et al. test whether vision-language models (VLMs) form truly multimodal text representations that aid tasks with latent visual structure. They construct a shape-counting task that is trivial with images but difficult from text coordinates. They find that VLMs perform no better on the text version than their language-only counterparts, but a self-distillation method that aligns text embeddings with image embeddings yields substantial gains.

Language models

Multi-hop retrieval from a shared KV cache gives hybrid models strictly deeper composition power

Eitan, Yehudai, and Maron analyze the expressive power of efficient hybrid sequence models, which pair a full-attention layer with cheaper recurrent or sparse layers. They prove that existing designs, including sparse top-κ access to the attention cache, need Ω(√n) capacity for two-function composition. Their proposed Multi-Hop Retrieval Attention (MuRA) block computes compositions of m functions at fixed size with m hops of retrieval, establishing a strict expressivity hierarchy.

Evaluation & benchmarks

Safety benchmark scores reflect training policy more than model capability

Jebraeeli et al. exploit an industrial accident where roughly 53,000 prompts were labeled under two different safety policies (moderator block vs. harmful content). Training ten guardrail models at two scales, they find that benchmark scores are heavily influenced by the labeling policy: HarmBench-copyright varies by 0.99 across arms, and over-refusal benchmarks vary by 53 percentage points. They also show that training corpora often contain benchmark prompts (e.g., 88% of JailbreakBench-benign is in training data), and validation accuracy tracks policy agreement (rho=+0.74) rather than detection capability (rho=+0.34).

Evaluation & benchmarks

Agent memory narrows LLM response diversity, limiting user access to information

Tan et al. introduce MemBubble, a benchmark of 1000 query-history pairs built from real user-assistant conversations, to measure how agent memory affects response diversity. Across six LLMs and five memory mechanisms, they find that memory processing reduces response entropy by 34.7% on average compared with providing the full interaction history. Simple user-side interventions fail to close this diversity gap.

Agents

Distillation overshoot lets smaller agents surpass teachers, and a new method preserves those gains.

The authors trained smaller language-model agents by on-policy distillation from stronger teachers and found a counterintuitive pattern: students often exceed the teacher mid-training, then regress. They attribute this to competing effects of decision repair and erosion, and introduce SPOD, which preserves successful student choices from the teacher's conflicting supervision. SPOD consistently beat ordinary distillation (up to 15.2 percentage points) and even surpassed the teacher by up to 20 points.

Efficiency & systems

Jointly co-compiling draft and target models boosts speculative decoding speed

The authors introduce Conjugate Compilation, a method that reframes speculative decoding as a cross-model compilation problem by jointly optimizing the small draft model and the larger target model within their shared execution on a single GPU. A self-improving agentic system couples an LLM with Monte Carlo tree search, proposing and evaluating cross-model plans based on actual co-located GPU performance, achieving speedups up to 1.59x and improving GPU utilization by up to 1.50x.

Efficiency & systems

Speculative decoding throughput gains are conditional on workload and serving conditions

The authors systematically evaluate when additional acceptance length in speculative decoding is worth the computational cost. By remeasuring released checkpoints and retraining six drafter recipes under shared conditions on two target models, they find that published method gaps shrink substantially. They identify two routes to improve acceptance—nearly free context/objective changes and more expensive token-to-token conditioning—and show that throughput gains depend on task entropy and serving concurrency.

Evaluation & benchmarks

State media articles now dominate English web crawl content

The authors introduce WorldStateMedia, an open dataset of 118 million state media articles in 114 languages, built by linking Fineweb web crawl data to outlet-level state control annotations. Auditing these corpora, they find editorially controlled state media has grown sharply in English crawls and is overrepresented in low-resource languages. A retrieval-augmented generation experiment shows that retrieving country-specific state media biases LLM answers toward that country's territorial claims.

Agents

Evidence annotations improve step-level credit for deep search agents

Luo and colleagues propose EG-GRPO, a reinforcement-learning method that turns evidence annotations in synthetic search data into rewards for individual retrieval steps. An LLM judge links each required claim to the first citation that supports it, allowing the method to track how an agent's knowledge develops during a search. Across five deep-search benchmarks, the authors report generally stronger performance than standard GRPO and several reward-enhanced or step-level alternatives.

Generative media

Robust prediction principle yields better latent spaces for diffusion models

The authors revisit REPA-E, a prior approach for improving latent diffusability, and find that removing the diffusion objective while retaining semantic prediction from corrupted latents gives comparable results. This motivates a general principle—robust prediction—which they instantiate in RoAR-VAE using two complementary objectives: RobustAlign (predicting pretrained semantic features) and RobustRecon (reconstructing the clean image). RoAR-VAE improves average generation benchmark performance by 2.19 points over the strongest baseline and boosts small-text reconstruction accuracy by 16.93 percentage points over FLUX.1-VAE.

Generative media

Video sampling needs both model likelihood and external physics guidance

Zheng et al. distinguish between unlikely errors produced during sampling and physically implausible behavior that a video model nevertheless considers likely. They use this decomposition to build HA-Sampler, which adds external physical guidance during latent refinement, and HA-Scorer, which estimates model likelihood to rank generated videos. Tests on Physics-IQ and VideoPhy show improvements over the compared sampling and scoring baselines, although the supplied text does not report effect sizes.

Generative media

Combining compression and adaptive inference for diffusion transformers without quality loss

The authors identify a Combination Gap: directly attaching existing adaptive reuse methods to a compressed diffusion transformer degrades sample quality (FID from 5.56 to 10.40–13.18 on ImageNet 256×256). They propose TamedFlow, which trains a compact DiT-B/2 student via cross-architecture feature alignment, residual velocity correction, and randomized rollout supervision, then deploys a 4M-parameter Learnable Trajectory Estimator to accept reliable student drafts or trigger teacher rescue. On ImageNet 256×256, TamedFlow achieves FID 2.58 at 2.25× measured speedup over the DDIM-50 teacher, and outperforms training-free adaptive baselines at comparable latency.

Evaluation & benchmarks

Utility metric reveals that accuracy doesn't guarantee responsible AI decisions

The authors present UtilityBench, a 15,000-instance benchmark that assigns sample-specific costs to errors using Best-Worst Scaling, and UtilityAUC, a metric that measures how well model confidence aligns with the utility of outcomes. Evaluating 20 state-of-the-art language models, they find that greater accuracy and more advanced architectures do not reliably translate to higher UtilityAUC, revealing a gap between problem-solving ability and responsible decision-making.

Agents

Global coordination of proof agents beats local repair in formal theorem proving

The authors present Maestro, an agentic framework for Lean proof development that replaces local repair of failed subgoals with global coordination. Workers provide structured failure reports, and a single coordinator decides on appropriate responses, such as guiding a stuck prover or replanning a flawed subtree. Maestro proves 34 out of 48 theorems from the June 2026 arXivLean release with Claude Opus 5, compared to 19 for the native agent, and outperforms all published provers on PutnamBench, Lean-IMO-Bench, and IMO 2026.

Reinforcement learning

Interventional step credit prunes redundant chain-of-thought while preserving accuracy

Guanda Li and colleagues propose interventional step credit (ISC), a causal measure of how much each chain-of-thought step influences the final answer, and use it to train models via interventional guidance policy optimization (IGPO). On two model scales across nine benchmarks, IGPO reduced average response length by up to 62% while improving macro-average accuracy by up to 8.4 percentage points over base models.

Generative media

World coordinates replace learned features for game model control

The authors propose ActionRoPE, a parameter-free interface that converts action-driven camera displacement into world-coordinate rotary positions for planar-camera game world models. This approach reduces revisit drift by 66% over the strongest baseline and generalizes across model sizes and out-of-distribution scenes, solving a core mismatch between learned feature conditioning and the geometric structure of top-down and isometric games.

Evaluation & benchmarks

An agentic framework that diagnoses and verifiably repairs foundation model failures

The authors introduce EvalRx, an open-source agentic framework that discovers systematic failure modes in foundation models, formulates falsifiable hypotheses, and verifies them before applying targeted repairs. In evaluations across 12 model family-modality combinations spanning Gemini, Qwen, Gemma, and Nemotron, EvalRx improved performance by +1.4 to +10.9 percentage points, with an average gain of +5.8 points.

Code & software

Security skills guide coding agents to only 11% fully correct vulnerability detection

Xue et al. systematically evaluate 37 public security skills for coding agents (Claude Code with four LLMs) on 100 real Linux kernel vulnerabilities. Across 14,800 runs, only 11.1% of detections were fully correct (vulnerable function, statement, and class). The authors propose SKILL-SIF, a self-improving framework that iteratively refines skills from missed vulnerabilities, improving fully correct detection from 2% to 16% on unseen vulnerabilities.

Generative media

Predicting velocity fields helps video models generate more realistic fluids

Zheng, Li, Deng and colleagues target a persistent weakness of video generators: smoke, fire and explosion debris often look detailed but move without coherent turbulence. Their system combines supervised training on Houdini simulations and real-world footage with preference optimization guided by predicted fluid velocity, producing more structured vortices, advection and fine-scale motion than the tested alternatives.

Generative media

Revising skipped diffusion steps with later feedback improves caching efficiency and quality.

The authors propose PoSTCache, a training-free framework that makes diffusion caching postdictive: predictions for skipped steps are first forecast, then revised using discrepancies observed at later full-computation steps. They also introduce Posterior Variance Reduction (PVR), an anchor selection strategy based on offline-profiled cross-timestep dependencies. On representative image and video generation models, PoSTCache improves reconstruction fidelity over existing caching methods at comparable or higher acceleration.

Evaluation & benchmarks

Southeast Asian language models still rely heavily on English representations

Han and colleagues introduce DeepSEA, a professionally translated benchmark covering mathematical and scientific reasoning, question answering, summarization and machine translation in 12 Southeast Asian languages. Their evaluation finds that leading frontier systems remain comparatively robust, while smaller models deteriorate sharply on low-resource languages and often perform better when using English as an intermediate language.

Agents

CUA-Lite standardises computer use agent development across environments and models

The authors present CUA-Lite, an open platform that standardises the components needed to develop computer use agents (CUAs)—agents that control desktop, browser, and mobile applications. By defining three abstractions (a unified environment interface, a unified supervised data format, and per-model harnesses shared across evaluation, RL, and SFT), the platform integrates 12 benchmarks, provides lightweight VM-free desktop sandboxes with over 30,000 verifiable tasks, and converts major public CUA datasets. The authors release reference scores for 15 models and show that supervised fine-tuning and reinforcement learning through the same harness improve open-weight models.

Agents

Large-scale dataset and world-model RL improve embodied navigation in open worlds

The authors propose Embodied World Agents (EWAs), agents that perceive and act across diverse open-world 3D environments, and release EmbodiedWorld-200K, a dataset of over 200K video samples with multi-level annotations. They demonstrate that offline pretraining on this data improves embodied planning, and that further RL post-training using a video world model as a scalable environment proxy yields clear gains on out-of-distribution scenes.

Evaluation & benchmarks

Benchmark reveals long-context models falter on state tracking and pattern learning

The authors introduce LEAPS, a collection of 12 novel datasets designed to evaluate long-context language models on state tracking and pattern learning, capabilities often overlooked by existing recall-focused benchmarks. Testing 30 API and open models at context lengths from 8K to 512K tokens, they find that models scoring near-perfect on recall tasks vary dramatically on these other abilities and degrade significantly as input length increases.

Agents

Self-evolving agents trade plasticity for stability in continual learning streams.

The authors test whether nonparametric self-evolving LLM agents, which adapt by rewriting prompts, memory, or code without updating model weights, can function as continual learners. Across four drifting task streams built from BIRD, BFCL, and ScienceWorld, they find that self-evolution improves aggregate performance on most streams but systematically sacrifices stability for plasticity, and that both self-modification and similarity-based retrieval suffer from interference or overwriting when task distributions shift.

Language models

Language model RL failures can guide targeted pretraining repairs

Wang and Chen show that reinforcement learning with verifiable rewards fails in recognizable, localized ways: a small set of phrases and operations strongly predicts whether a reasoning rollout will end incorrectly. They use those diagnostic n-grams to retrieve just 35 million tokens from existing training corpora, then continue pretraining before rerunning reinforcement learning, outperforming equally sized random-data controls in 10 of 11 settings.

Language models

Spherical geometry simplifies adaptive-loop reasoning and improves halting efficiency

The authors introduce Spherical Fixed-Point Reasoners (SFPRM), which perform a damped fixed-point loop on the hypersphere of normalized transformers. On Sudoku-Extreme, Maze-Hard, and Mini-ARC, SFPRM achieves test accuracies of 96.6%, 87.9%, and 59.1%, outperforming Fixed-Point Reasoners (FPRM) and other baselines while halting up to 2.7 times earlier at equal or higher accuracy. The angular geometry also provides interpretable representations: token-input angles encode puzzle structure and predict answer correctness.

Reinforcement learning

Varying sampled video frames strengthens reinforcement learning for temporal reasoning

Sun, Wang and Li address a weakness in Group Relative Policy Optimization for video: rollouts normally see identical frames, so they may all succeed or fail and provide little comparative learning signal. Their FrameGRPO method varies frame density within each rollout group and selectively rewards successful lower-frame trajectories when every full-frame reference rollout fails. The authors report consistent gains over standard GRPO across seven video benchmarks.