CV

Research Scientist

Physis AI

• World model startup building physically grounded world foundation models with reinforcement learning. Backed by Hillhouse Ventures and Yanyuan Capital.

Research Intern

PKU-Alignment Group, Peking University

Advised by Prof. Yaodong Yang

• Led the development of TruthfulVQA, the first benchmark for multimodal truthfulness evaluation (ACL 2026).
• Led the development of Debate with Images, a visually grounded multi-agent debate framework for multimodal deception detection, along with MM-DeceptionBench, the first benchmark for multimodal deception.
• Co-first authored the AI Deception Survey, with Turing Award laureate Andrew Yao as corresponding author.
• Core contributor to Align-Anything (4,600+ stars on GitHub), an all-modality alignment framework.
• Core contributor to Eval-Anything, a comprehensive safety evaluation framework for multimodal models.

Research Intern

HKGAI R&D Center / HKUST

• Contributed to HKGAI-V1, the Hong Kong government’s first locally fine-tuned generative AI model based on DeepSeek, supporting Cantonese, Mandarin, and English with localized safety alignment.

B.S. in Artificial Intelligence

Peking University

Yuanpei College

• Honors: Yuanpei Young Scholar; Boya Scholarship; Soong Ching Ling Future Scholarship; Beijing Natural Science Foundation QiYan Research Program; Freshman Scholarship (First Prize)
• Technical Skills: Python, PyTorch, vLLM, DeepSpeed, Ray, CUDA, C/C++, LaTeX

When Slower Isn't Truer: Inverse Scaling Law of Truthfulness in Multimodal Reasoning

ACL 2026

Sitong Fang, Wenjing Cao, Jiahao Li, Xuyao Wang, Chi-Min Chan, Sirui Han, Juntao Dai, Yike Guo, Yaodong Yang, Jiaming Ji

Debate with Images: Detecting Deceptive Behaviors in Multimodal LLMs

Under Review

Sitong Fang, Shiyi Hou, Kaile Wang, Boyuan Chen, Donghai Hong, Jiayi Zhou, Juntao Dai, Yaodong Yang, Jiaming Ji

AI Deception: Risks, Dynamics, and Controls

Under Review

Boyuan Chen*, Sitong Fang*, Jiaming Ji*, …, Yaodong Yang, Tiejun Huang, Ya-Qin Zhang, HongJiang Zhang, Andrew Yao. (* Equal contribution)

Yuanpei Young Scholar, Peking University

10 annual recipients

Beijing Natural Science Foundation Undergraduate QiYan Research Program

Sole recipient in cohort

Soong Ching Ling Future Scholarship

Boya Scholarship, Peking University

CMSC Scholarship, Peking University

Academic Excellence Award, Peking University

Social Service Award, Peking University

Freshman Scholarship (First Prize), Peking University

Ranked 1st in Fujian Province, National College Entrance Exam (Science)