Research

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

2566 articles · page 43 of 54 · The Research front page

Vision

Grounding long-video memories in visual identity lets QA systems track objects across days

The authors introduce Grounded Entity Biographies (GEB), a long-video memory framework that groups visually grounded observations of the same physical instance across clips into retrievable biographies. On four benchmarks, including day-long and week-long recordings, GEB outperforms prior memory frameworks in both multiple-choice and open-ended question answering. On EgoLifeQA it reaches 72.0%, 4.4 percentage points above the best published result.

Reinforcement learning

Self-privileged critic improves value estimation for RLVR

Liang et al. propose πPPO, an actor-critic framework for reinforcement learning with verifiable rewards (RLVR) that conditions the critic on contrastive evidence from successful and failed rollouts of the same prompt. This self-privileged formulation consistently improves value-estimation accuracy and outperforms standard PPO and critic-free baselines on challenging mathematical reasoning benchmarks, while also supporting smaller asymmetric critics.

Vision

Multi-agent framework generates spatial QA data via code execution

Ying et al. introduce Exemplar2VQA, a multi-agent framework that synthesizes large-scale 3D spatial question-answer pairs in simulated environments. By converting user-defined exemplar queries into deterministic code via specialized agents, the system avoids hallucinations common to LLM-based generation. Fine-tuning Qwen2.5-VL models on this synthetic indoor data improves performance on multiple spatial benchmarks, including outdoor and mixed-scene settings.

Language models

Latent feedback helps Transformers carry information across generation steps

Tirosh, Amos and Geva introduce LIFT, a Transformer architecture that feeds a compact continuous state from each generated position into the processing of the next. Across models from 135 million to 1 billion parameters, the authors report better language modeling, reasoning and procedural-task performance than standard Transformers trained on the same number of tokens, with competitive or better results when training compute is matched.

Agents

Specialized executors follow declared agent plans more faithfully

Oota et al. separate agent planning into two problems: choosing an appropriate planning mode and executing that mode faithfully. Across four benchmarks and three language models, generic Plan+ReAct agents frequently abandoned their declared structure, while pattern-specific executors largely closed this execution gap. The remaining weakness was selection, since models did not reliably choose the best mode for each task.

Reinforcement learning

Fisher-Rao prompt curricula make GRPO training more rollout-efficient

Okonkwo et al. analyze why group relative policy optimization wastes computation on prompts whose sampled answers are either all correct or all incorrect, producing no learning signal. They derive a prompt curriculum in Fisher-Rao arc-length coordinates and implement it in ARCUS, which outperformed standard GRPO and dynamic sampling across six mathematical reasoning benchmarks and three model backbones.

Agents

Counterfactual credit teaches language models which memories stay useful

Tang, Liu and Sarabi address a central problem in persistent language-model memory: a rewrite may help only much later, and its apparent value may actually come from information already stored. Their Memory Gain Policy Optimization method compares updated and prior memory states to isolate the value created by each rewrite, improving document-level information extraction while cutting average memory length by nearly 80% from the initial policy.

Agents

Retrieving existing agent skills improves optimization across different execution harnesses

Chu et al. introduce Retrieval-Augmented Skill Optimization, or RASO, for improving the natural-language instructions that guide agents inside particular tool and execution environments. Across four benchmarks and two language models, the authors report that retrieving and adapting existing skills consistently outperformed optimization baselines that lacked retrieval during initialization and updating.

Reinforcement learning

Self-generated failure summaries help models solve previously impossible tasks

Kirchhof et al. introduce RLTL;DR, a training method that turns verifier feedback from failed coding and tool-use attempts into short, model-generated insights for subsequent attempts. On tasks the base model could not solve in 128 tries, the method raised Pass@1 from 0 to 1 percent under standard training to as high as 31 percent, while retaining 12 to 13 percent when the insights were removed at evaluation.

Language models

Companion model sharpens LLM confidence without harming task performance

The authors propose concurrent confidence calibration, where confidence is learned alongside capability improvement during reinforcement learning from verifiable rewards (RLVR). Their method, CoCal (Companion Confidence Calibration), trains a separate lightweight model on rollout hidden states and verifier feedback, decoupling confidence estimation from policy optimization. Experiments on Qwen3-8B and Qwen3-14B show that CoCal improves confidence estimation without sacrificing task accuracy, outperforming both RL-based concurrent methods and post-hoc calibration.

Language models

Training a concept generator improves LLM reasoning over repeated sampling.

The authors propose a method where a small concept generator is trained using reinforcement learning to produce high-level concepts (e.g., hints, strategies) that maximize the downstream success of a frozen, larger answer generator. On hard mathematical reasoning problems, this learned search policy substantially improves pass@k over naive repeated sampling at the same answer generation allocation, transfers to other answer generators, and outperforms concepts from much larger untuned models.

Robotics & embodied AI

Robot self-improvement stalls when perception, skill chains and tests mislead

Wang built an agentic robotics system that diagnoses failures, writes skills or installs external models, and tests changes without human-written robot code. The agent successfully discovered some missing capabilities, but its improvements did not accumulate into task success because relational perception, sequential skill testing and the evaluation harness constrained what it could learn.

Efficiency & systems

Elastic phase sharing improves efficiency in agentic LLM serving

Xu et al. address a mismatch in disaggregated LLM serving, where separate pools handle prompt processing, called prefill, and token generation, called decode, even though demand for each phase changes rapidly. Across public and internal traffic traces, Crossflow increased token throughput by 16.2 to 17.4% on geometric mean over static partitioning, while reducing average time to first token at every evaluated load.