Xuhan Tong

Tsinghua University · Mathematics & Physics + Software Engineering

Portrait of Xuhan Tong

Toward stable and reliable inference in language models.

My work develops theoretical and empirical accounts of when an LLM can recover a supported inference path, why it may instead follow a salient shortcut, and how a system can diagnose and repair the failure.

01 · REACH

In-context learning

Characterizing how demonstration quality, prompt consistency, and pretraining support govern generalization to unseen tasks.

02 · FAILURE

Hallucination mechanisms

Studying when high-frequency associations overpower decisive prompt constraints, producing inference misalignment despite available knowledge.

03 · REPAIR

Detection and intervention

Separating knowledge gaps, context distraction, compute insufficiency, and calibration failure so that mitigation can target the active cause.

04 · STRATEGY

Multi-agent reliability

Investigating communication and coordination strategies for agents solving complex tasks under heterogeneous and conflicting constraints.

Selected work

2026

Understanding Why Language Models Hallucinate: Testing Reasoning Against Priors

Yangfan Hu*, Xuhan Tong*, Haoyue Bai*, Xi Ding, Shashank Muralidhar Bharadwaj, Siyang Cao, Robert Nowak, Jiawei Zhang

arXiv preprint · * Equal contribution

2026

Demonstrations, CoT, and Prompting: A Theoretical Analysis of ICL

Xuhan Tong, Yuchen Zeng, Jiawei Zhang

COLM 2026 Workshop on Scientific Understanding of Foundation Models

Research experience

University of Wisconsin–Madison

Research Assistant · Advisor: Prof. Jiawei Zhang · October 2024 — Present

My research centers on reliable language-model inference. I have developed theoretical accounts of in-context learning and Chain-of-Thought prompting, studied hallucination as inference misalignment between prompt evidence and pretraining priors, and investigated counterfactual interventions that distinguish knowledge-deployment failures from ignorance.

My current work extends this perspective to multi-agent systems, examining how specialized agents communicate and coordinate when solving complex tasks under multiple constraints.

Education

B.S., Mathematics & Physics + Software Engineering

Tsinghua University, Beijing

Selected honors

  • 2025Comprehensive Outstanding Scholarship
  • 2024Science & Technology Innovation Outstanding Scholarship
  • 2024Academic Excellence Scholarship