Complex & Algebraic Geometry · 数学

Yan He贺岩

Assistant Professor (Jiangshi) by special appointment (Quanzhitepin), also a faculty postdoc (Shizi Bohou) · School of Mathematics & Information Science, Guangzhou University

I work in complex and algebraic geometry — the analytic side of it. My research centers on the Ohsawa–Takegoshi extension theorem and pluripotential theory, with separate interests in Nevanlinna theory and hyperbolicity. I also build things: small, sharp software systems that let me work the way I want to.

Research

The optimal constant, and what geometry hides inside it

The Ohsawa–Takegoshi extension theorem is one of the central analytic tools of modern complex and algebraic geometry: it guarantees that a holomorphic function defined on a subvariety extends to the whole space, with explicit control. The size of the constant in that control is not a technicality — it ties directly to Bergman kernel estimates, the Suita conjecture, Skoda's division theorem, and the existence of sections in algebraic geometry.

Extension with controlled L² norm — the constant C is where the geometry lives.

Using the Berndtsson–Lempert method together with geodesics in the space of Kähler metrics and the Ross–Witt Nyström correspondence, I work toward understanding and computing this optimal constant — and toward turning that understanding into new proofs of Skoda's division theorem and new effective criteria around the existence of holomorphic sections of KX + L (the Fujita-conjecture circle of problems).

A separate line of work runs through value distribution theory: developing a Nevanlinna-theoretic notion of hyperbolicity, and asking whether it is equivalent to Kobayashi hyperbolicity.

Selected Publications

Papers

preprint
Yan He, Johannes Testorf, Xu Wang · arXiv:2311.03840
2021
Nevanlinna and algebraic hyperbolicity
Yan He, Min Ru · International Journal of Mathematics
2021
Nevanlinna theory through the Brownian motion
Xianjing Dong, Yan He, Min Ru · Science China Mathematics
2021
A generalized subspace theorem for closed subschemes in subgeneral position
Journal of Number Theory

Current work in preparation: optimal constants in the Ohsawa–Takegoshi theorem via Berndtsson–Lempert, and partial Bergman kernel estimates on compact Riemann surfaces.

Path

Where I've been

2026 —
Assistant Professor
Guangzhou University · School of Mathematics & Information Science
2022 – 2025
Postdoctoral Researcher
Norwegian University of Science and Technology (NTNU), Trondheim · with Xu Wang
2016 – 2021
Ph.D. in Mathematics
University of Houston · advisor Min Ru
2012 – 2016
B.S. in Mathematics
Renmin University of China, Beijing
AI & Building

I build the tools I work with

Alongside the mathematics, I design and build software — usually small, sharp systems that get language models to do real, reliable work instead of demos. The instinct is the same one I bring to a proof: find the actual structure, then make it clean.

Flagship · 2026

A Modular Framework for AI-Assisted Math Research

A document system that makes the dependency structure of mathematics explicit: every lemma, computation, or definition is a node in a directed acyclic graph, with machine-readable links to its context, prerequisites, and consequents. Numbered, individually-annotated proof steps let me tell an AI collaborator exactly which step is unclear — and any subtopic can be promoted to a self-contained subproject, anchored to its parent. The design borrows a principle from scheme theory: there is no absolute object, only an object over its base.

github.com/dazhima/math-ai-framework →

complex geometry L² methods Nevanlinna theory AI agents knowledge systems automation self-hosting
Others

Other things I keep here

Contact

Get in touch

Office
Room 222, 行政西楼后座 · School of Mathematics & Information Science, Guangzhou University · University Town, Panyu, Guangzhou

Open to collaboration in complex/algebraic geometry, students interested in several complex variables, and conversations about AI-assisted research workflows.