Hanxuan Li 李瀚轩

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Hanxuan Li
Undergraduate student
Turing Class, College of Computer Science and Technology,
Zhejiang University
Email: lihanxuan23@gmail.com
Github

About me

I am a fourth-year undergraduate student (2022.9 – Present) in Turing Class, Chu Kochen Honors College, Zhejiang University. I am also an incoming PhD student at SphereLab, the Chinese University of Hong Kong, advised by Prof. Weiyang Liu. During my undergraduate studies, I have had the privilege of working with Prof. Yulun Zhang and Prof. Huan Wang.

My research vision is to understand the principles underlying large language model pretraining, with emphasis on optimization, architecture, and scaling laws. I am also interested in whether neural networks acquire structured internal models of tasks and environments and whether they can support causal representation and reasoning beyond surface correlation.

Pretraining principles

  • Optimization. Algorithms and dynamics of LLM pretraining (e.g., stability, implicit bias, and efficiency).
  • Architecture. Inductive biases in large-scale model designs, with emphasis on neural memory.
  • Scaling laws. How performance and behavior scale with width, depth, and data, and how these axes interact.

News

Selected Papers

(* denotes equal contribution, † denotes corresponding author)

Pion: A Spectrum-Preserving Optimizer via Orthogonal Equivalence Transformation
Kexuan Shi*, Hanxuan Li*, Zeju Qiu, Yandong Wen, Simon Buchholz, Weiyang Liu
arXiv preprint
tl;dr: A spectrum-preserving optimizer that updates each weight matrix via left and right orthogonal transformations, keeping singular values fixed while modulating geometry; competitive for LLM pretraining and finetuning.

For the full list, see Publications.