collaborators

6 papers

cs.LG2026

Online KL-Regularized Reinforcement Learning with Function Approximation under Misspecification

Haoyang Hong, Zichen Wang, Quanquan Gu +1

We study KL-regularized contextual bandits and episodic reinforcement learning (RL) under general function approximation with model misspecification. Existing guarantees rely on re…

cs.LG2026

Fast Rates for Offline Contextual Bandits with Forward-KL Regularization under Single-Policy Concentrability

Qingyue Zhao, Kaixuan Ji, Heyang Zhao +1

\emph{Kullback-Leibler} (KL) regularization is ubiquitous in reinforcement learning algorithms in the form of \emph{reverse} or \emph{forward} KL. Recent studies have demonstrated…

cs.LG2026

Dimension-Independent Convergence of Underdamped Langevin Monte Carlo in KL Divergence

Shiyuan Zhang, Qiwei Di, Xuheng Li +1

Underdamped Langevin dynamics (ULD) is a widely-used sampler for Gibbs distributions , and is often empirically effective in high dimensions. However, existing no…

cs.LG2025

Variance-Aware Feel-Good Thompson Sampling for Contextual Bandits

Xuheng Li, Quanquan Gu

Variance-dependent regret bounds have received increasing attention in recent studies on contextual bandits. However, most of these studies are focused on upper confidence bound (U…

cs.LG2025

Best-of-Majority: Minimax-Optimal Strategy for Pass@ Inference Scaling

Qiwei Di, Kaixuan Ji, Xuheng Li +2

LLM inference often generates a batch of candidates for a prompt and selects one via strategies like majority voting or Best-of- N (BoN). For difficult tasks, this single-shot sele…

cs.LG2025

Understanding SGD with Exponential Moving Average: A Case Study in Linear Regression

Xuheng Li, Quanquan Gu

Exponential moving average (EMA) has recently gained significant popularity in training modern deep learning models, especially diffusion-based generative models. However, there ha…