I am a Ph.D. student in Computer Science at Brigham Young University (BYU), advised by Prof. Porter Jenkins, and I also collaborate with Prof. Weitong Zhang (UNC). I received my M.S. from Penn State (IST), where I was advised by Prof. Fenglong Ma (PSU), and I earned my B.S. in Mathematics from Shenzhen University.

My early work focused on fairness in federated learning. Recently, my primary research direction has moved to LLM reasoning, with a focus on post-training and test-time scaling (TTS). I am always happy to connect and discuss related ideas.

🔥 News

  • 2026.01:  🎉 One paper was accepted to ICLR 2026.

📝 Publications

LLM Reasoning

  • Provable and Practical In-Context Policy Optimization for Self-Improvement
    Tianrun Yu, Yuxiao Yang, Zhaoyang Wang, Kaixiang Zhao, Porter Jenkins, Xuchao Zhang, Chetan Bansal, Huaxiu Yao, Weitong Zhang
    ICLR 2026
    PDF

Federated Learning

  • Towards Collaborative Fairness in Federated Learning Under Imbalanced Covariate Shift
    Tianrun Yu, Jiaqi Wang, Haoyu Wang, Mingquan Lin, Han Liu, Nelson S. Yee, Fenglong Ma
    KDD 2025
    PDF

  • When the Server Steps In: Calibrated Updates for Fair Federated Learning
    Tianrun Yu, Kaixiang Zhao, Cheng Zhang, Anjun Gao, Yueyang Quan, Zhuqing Liu, Minghong Fang
    WiOpt 2026
    PDF

🎖 Honors and Awards

  • 2023: National Scholarship of China
  • 2022: Mathematical Contest in Modeling (MCM/ICM), Honorable Mention (F Award)
  • 2021: Shenzhen University Top-notch Innovative Talents Scholarship

📖 Educations

  • 2026.01 - Present, Ph.D. in Computer Science, Brigham Young University
  • 2024.09 - 2025.12, M.S. in Informatics, The Pennsylvania State University
  • 2020.09 - 2024.07, B.S. in Mathematics, Shenzhen University

💻 Internships