collaborators

14 papers

cs.LG2026

Reformulate LLM Reinforcement Learning for Efficient Training under Black-box Discrepancy

Jiashun Liu, Runze Liu, Xu Wan +3

Reinforcement Learning (RL) has emerged as a pivotal post-training paradigm, yet it frequently suffers from unpredictable sub-optimum performance or even training collapses. Recent…

cs.LG2026

When RL Fails after SFT: Rejuvenating Model Plasticity for Robust SFT-to-RL Handoff

Runze Liu, Jiashun Liu, Xu Wan +2

Supervised Fine-Tuning (SFT) followed by Reinforcement Learning (RL) has become a standard pipeline for Large Language Model (LLM) post-training. SFT is expected to provide a usefu…

cs.LG2026

Local Guidance, Global Impact: Gaussian-Reshaped Trust Region Unlocks Behavior Transitions

Bingxu Liu, Jiashun Liu, Johan Obando-Ceron +5

While Proximal Policy Optimization (PPO) demonstrates strong performance in stationary settings, we show that its standard optimization paradigm struggles in continual and non-stat…

cs.CL2026

When Importance Sampling Misallocates Credit: Asymmetric Ratios for Outcome-Supervised RL

Jiakang Wang, Runze Liu, Qingpeng Cai +7

Reinforcement learning (RL) has shown great promise in large language models (LLMs) post-training, which typically rely on token-level clipping to maintain stability during optimiz…

cs.CL2026

Stabilizing Knowledge, Promoting Reasoning: Dual-Token Constraints for RLVR

Jiakang Wang, Runze Liu, Fuzheng Zhang +3

Reinforcement Learning with Verifiable Rewards (RLVR) has become an effective post-training method for improving the reasoning abilities of Large Language Models (LLMs). However, e…

cs.LG2026

Temporal Difference Learning with Constrained Initial Representations

Jiafei Lyu, Jingwen Yang, Zhongjian Qiao +5

Recently, there have been numerous attempts to enhance the sample efficiency of off-policy reinforcement learning (RL) agents when interacting with the environment, including archi…