activity
20232026
most citedChain of Preference Optimization: Improving Chain-of-Thought Reasoning in LLMs

6 citations · 37 across the 30 of their papers we have counts for

collaborators

33 papers

cs.LG2026

Rethinking the Trust Region in LLM Reinforcement Learning

Penghui Qi, Xiangxin Zhou, Zichen Liu +4

Reinforcement learning (RL) has become a cornerstone for fine-tuning Large Language Models (LLMs), with Proximal Policy Optimization (PPO) serving as the de facto standard algorith…

cs.LG2025

Defeating the Training-Inference Mismatch via FP16

Penghui Qi, Zichen Liu, Xiangxin Zhou +4

Reinforcement learning (RL) fine-tuning of large language models (LLMs) often suffers from instability due to the numerical mismatch between the training and inference policies. Wh…

cs.LG2025

Nonparametric Data Attribution for Diffusion Models

Yutian Zhao, Chao Du, Xiaosen Zheng +2

Data attribution for generative models seeks to quantify the influence of individual training examples on model outputs. Existing methods for diffusion models typically require acc…

cs.CL2025

Variational Reasoning for Language Models

Xiangxin Zhou, Zichen Liu, Haonan Wang +5

We introduce a variational reasoning framework for language models that treats thinking traces as latent variables and optimizes them through variational inference. Starting from t…

cs.CL2025

Language Models Can Learn from Verbal Feedback Without Scalar Rewards

Renjie Luo, Zichen Liu, Xiangyan Liu +5

LLMs are often trained with RL from human or AI feedback, yet such methods typically compress nuanced feedback into scalar rewards, discarding much of their richness and inducing s…

cs.LG2025

Continual Reinforcement Learning by Planning with Online World Models

Zichen Liu, Guoji Fu, Chao Du +2

Continual reinforcement learning (CRL) refers to a naturalistic setting where an agent needs to endlessly evolve, by trial and error, to solve multiple tasks that are presented seq…

cs.LG2025

Reinforcing General Reasoning without Verifiers

Xiangxin Zhou, Zichen Liu, Anya Sims +6

The recent paradigm shift towards training large language models (LLMs) using DeepSeek-R1-Zero-style reinforcement learning (RL) on verifiable rewards has led to impressive advance…

cs.CR2025

Lifelong Safety Alignment for Language Models

Haoyu Wang, Zeyu Qin, Yifei Zhao +4

LLMs have made impressive progress, but their growing capabilities also expose them to highly flexible jailbreaking attacks designed to bypass safety alignment. While many existing…

cs.LG2025

Optimizing Anytime Reasoning via Budget Relative Policy Optimization

Penghui Qi, Zichen Liu, Tianyu Pang +3

Scaling test-time compute is crucial for enhancing the reasoning capabilities of large language models (LLMs). Existing approaches typically employ reinforcement learning (RL) to m…

cs.AI2025

FlowReasoner: Reinforcing Query-Level Meta-Agents

Hongcheng Gao, Yue Liu, Yufei He +6

This paper proposes a query-level meta-agent named FlowReasoner to automate the design of query-level multi-agent systems, i.e., one system per user query. Our core idea is to ince…

cs.LG2025★ 6 cited

Understanding R1-Zero-Like Training: A Critical Perspective

Zichen Liu, Changyu Chen, Wenjun Li +5

DeepSeek-R1-Zero has shown that reinforcement learning (RL) at scale can directly enhance the reasoning capabilities of LLMs without supervised fine-tuning. In this work, we critic…

cs.CL2025

Improving Your Model Ranking on Chatbot Arena by Vote Rigging

Rui Min, Tianyu Pang, Chao Du +3

Chatbot Arena is a popular platform for evaluating LLMs by pairwise battles, where users vote for their preferred response from two randomly sampled anonymous models. While Chatbot…

cs.LG2024

Sample-Efficient Alignment for LLMs

Zichen Liu, Changyu Chen, Chao Du +2

We study methods for efficiently aligning large language models (LLMs) with human preferences given budgeted online feedback. We first formulate the LLM alignment problem in the fr…

cs.CR2024★ 1 cited

Denial-of-Service Poisoning Attacks against Large Language Models

Kuofeng Gao, Tianyu Pang, Chao Du +3

Recent studies have shown that LLMs are vulnerable to denial-of-service (DoS) attacks, where adversarial inputs like spelling errors or non-semantic prompts trigger endless outputs…

cs.AI2024★ 1 cited

Scaling up Masked Diffusion Models on Text

Shen Nie, Fengqi Zhu, Chao Du +5

Masked diffusion models (MDMs) have shown promise in language modeling, yet their scalability and effectiveness in core language tasks, such as text generation and language underst…

cs.CL2024

LightTransfer: Your Long-Context LLM is Secretly a Hybrid Model with Effortless Adaptation

Xuan Zhang, Fengzhuo Zhang, Cunxiao Du +4

Scaling language models to handle longer contexts introduces substantial memory challenges due to the growing cost of key-value (KV) caches. Motivated by the efficiency gains of hy…

cs.CV2024

Meta-Unlearning on Diffusion Models: Preventing Relearning Unlearned Concepts

Hongcheng Gao, Tianyu Pang, Chao Du +3

With the rapid progress of diffusion-based content generation, significant efforts are being made to unlearn harmful or copyrighted concepts from pretrained diffusion models (DMs)…

cs.CL2024★ 2 cited

When Attention Sink Emerges in Language Models: An Empirical View

Xiangming Gu, Tianyu Pang, Chao Du +5

Language Models (LMs) assign significant attention to the first token, even if it is not semantically important, which is known as attention sink. This phenomenon has been widely a…

cs.CL2024★ 1 cited

A Closer Look at Machine Unlearning for Large Language Models

Xiaojian Yuan, Tianyu Pang, Chao Du +3

Large language models (LLMs) may memorize sensitive or copyrighted content, raising privacy and legal concerns. Due to the high cost of retraining from scratch, researchers attempt…

cs.CL2024

Cheating Automatic LLM Benchmarks: Null Models Achieve High Win Rates

Xiaosen Zheng, Tianyu Pang, Chao Du +3

Automatic LLM benchmarks, such as AlpacaEval 2.0, Arena-Hard-Auto, and MT-Bench, have become popular for evaluating language models due to their cost-effectiveness and scalability…

cs.LG2024★ 3 cited

Improved Techniques for Optimization-Based Jailbreaking on Large Language Models

Xiaojun Jia, Tianyu Pang, Chao Du +5

Large language models (LLMs) are being rapidly developed, and a key component of their widespread deployment is their safety-related alignment. Many red-teaming efforts aim to jail…

cs.CL2024

Bootstrapping Language Models with DPO Implicit Rewards

Changyu Chen, Zichen Liu, Chao Du +5

Human alignment in large language models (LLMs) is an active area of research. A recent groundbreaking work, direct preference optimization (DPO), has greatly simplified the proces…

cs.CL2024★ 6 cited

Chain of Preference Optimization: Improving Chain-of-Thought Reasoning in LLMs

Xuan Zhang, Chao Du, Tianyu Pang +3

The recent development of chain-of-thought (CoT) decoding has enabled large language models (LLMs) to generate explicit logical reasoning paths for complex problem-solving. However…

cs.CL2024★ 2 cited

Improved Few-Shot Jailbreaking Can Circumvent Aligned Language Models and Their Defenses

Xiaosen Zheng, Tianyu Pang, Chao Du +3

Recently, Anil et al. (2024) show that many-shot (up to hundreds of) demonstrations can jailbreak state-of-the-art LLMs by exploiting their long-context capability. Nevertheless, i…