← Search

Zhihan Liu

11 accepted papers

2025

BRiTE: Bootstrapping Reinforced Thinking Process to Enhance Language Model Reasoning

ICML 2025poster

Large Language Models (LLMs) have demonstrated remarkable capabilities in complex reasoning tasks, yet generating reliable reasoning processes remains a significant challenge. We present a unified probabilistic framework that formalizes LLM reasoning through a novel graphical model incorporating lat…

Cited by 1SourcePDFScholar
2025

Reward-Augmented Data Enhances Direct Preference Alignment of LLMs

ICML 2025poster

Preference alignment in Large Language Models (LLMs) has significantly improved their ability to adhere to human instructions and intentions. However, existing direct alignment algorithms primarily focus on relative preferences and often overlook the qualitative aspects of responses, despite having…

2025

Toward Optimal LLM Alignments Using Two-Player Games

EMNLP 2025

Alignment of large language models (LLM) is a process that ensures the model’s responses to user prompts align with human intentions and social values. This optimization typically relies on pre-collected prompts. The collection of these prompts often either requires careful human interventions or pr

2024

Provably Mitigating Overoptimization in RLHF: Your SFT Loss is Implicitly an Adversarial Regularizer

NeurIPS 2024poster

Aligning generative models with human preference via RLHF typically suffers from overoptimization, where an imperfectly learned reward model can misguide the generative model to output even undesired responses. We investigate this problem in a principled manner by identifying the source of the issue…

Cited by 49SourcePDFScholar
2024

Reason for Future, Act for Now: A Principled Architecture for Autonomous LLM Agents

ICML 2024poster

Large language models (LLMs) demonstrate impressive reasoning abilities, but translating reasoning into actions in the real world remains challenging. In particular, it is unclear how to complete a given task provably within a minimum number of interactions with the external environment, e.g., throu…

Cited by 6SourcePDFScholar
2023

Guarded Policy Optimization with Imperfect Online Demonstrations

ICLR 2023top-25%

The Teacher-Student Framework (TSF) is a reinforcement learning setting where a teacher agent guards the training of a student agent by intervening and providing online demonstrations. Assuming optimal, the teacher policy has the perfect timing and capability to intervene in the learning process of…

2023

Maximize to Explore: One Objective Function Fusing Estimation, Planning, and Exploration

NeurIPS 2023spotlight

In reinforcement learning (RL), balancing exploration and exploitation is crucial for achieving an optimal policy in a sample-efficient way. To this end, existing sample- efficient algorithms typically consist of three components: estimation, planning, and exploration. However, to cope with general…

2022

Learning from Demonstration: Provably Efficient Adversarial Policy Imitation with Linear Function Approximation

ICML 2022spotlight

In generative adversarial imitation learning (GAIL), the agent aims to learn a policy from an expert demonstration so that its performance cannot be discriminated from the expert policy on a certain predefined reward set. In this paper, we study GAIL in both online and offline settings with linear f…

Cited by 25SourcePDFScholar