Xiang Li

李想

Math PhD Student — Algebra & Number Theory

The University of Edinburgh · Hodge Institute

X.Li-198@sms.ed.ac.uk · GitHub · ORCID

Home

Welcome to my personal website! Here is the definition of me.

Definition 1.1

I'm Xiang Li 李想, a math PhD student of algebra and number theory in the University of Edinburgh working with Prof. Minhyong Kim since 2023. My interests are in algebraic number theory and arithmetic geometry. To be more specific, I am interested in non-abelian Chabauty methods, which provide an efficient way to find rational points on a curve.

Remark 1.2

Am I the first person coming up with an idea to make the personal website look like a math book that contains definition/remark etc.?

Proposition 1.3

In workdays, you can find me on the fifth floor of the Bayes Centre of the University of Edinburgh.

Proof.

The address of the Bayes Centre is 47 Potterrow, Edinburgh, United Kingdom, EH8 9BT. Find me there!

CV

You can find my detailed CV (curriculum vitae) here. Below is my education background.

  1. Sep 2023 – Now
    PhD in Mathematics

    The University of Edinburgh, School of Mathematics (Hodge Institute)

  2. Oct 2022 – Jun 2023
    MASt in Mathematics (Part III)

    University of Cambridge, Department of Pure Mathematics and Mathematical Statistics

  3. Sep 2020 – May 2022
    BSc in Mathematics

    The University of Edinburgh, School of Mathematics

  4. Sep 2018 – Jun 2020
    BSc in Mathematics

    South China University of Technology, School of Mathematics

Research

Recent Research Interests

With Martin Lüdtke, we establish foundations for the Chabauty–Kim method over number fields for the thrice-punctured line \(X = \mathbb{P}^1 \setminus \{0,1,\infty\}\). We investigate Kim's Conjecture for \(X\) over quadratic fields, verifying it in some cases and showing it fails in others. For imaginary quadratic fields \(K\) where \(S\) is empty or consists of a single Galois-unstable prime, we provide a proof of the \(S\)-Selmer section conjecture based on Chabauty–Kim methods.

Preprints

Expository Notes

Talks

  • Chabauty–Kim Methods over Number Fields: \(\mathbb{P}^1\backslash \left\{0,1,\infty\right\}\) 2 Jul 2026, 16:30 · MPIM Lecture Hall, Max Planck Institute for Mathematics

    Speed talk at ChaBONNty Conference. See the slides here.

  • S-integral Points on the Thrice-punctured Line over Cyclotomic Fields 5 Sep 2025, 15:00–15:30 · C17 Pope Building, University of Nottingham

    Young Researchers in Algebraic Number Theory VII

  • Rigid Geometry and Coleman Function 7 Feb 2025, 14:55–15:45 · Room 110, School of Mathematics and Statistics, University of Glasgow

    The GEARS seminar

  • Introduction to Chabauty–Kim Methods on S-unit Equations 2 Aug 2024, 14:30–15:00 · TCC Room, Mathematical Institute, University of Oxford

    Young Researchers in Algebraic Number Theory VI

  • Tannakian Category, Unipotent Completion, and de Rham Fundamental Group 1 Dec 2023, 10:45–11:15 · ICMS

    Examples Showcase at GlaMS

  • Euler's Totient Theorem and the Prime Number Theorem 16 Feb 2023, 16:00–17:00 · Zoom / Huxley 410, Imperial College

    (with Ella Yu) — Seminar of London Learning Lean. Watch the recording here. See the slides here.

Travel

Teaching

Past Tutoring

2025-2026 Semester 2
2025-2026 Semester 1
2024-2025 Semester 2
2024-2025 Semester 1

Also, I am a tutor for the MathsBase.

2023-2024 Semester 2
[MATH10077] Algebraic Topology

Codes

Computing polylogarithmic Chabauty–Kim loci over number fields

Sage code for the paper "Polylogarithmic Chabauty–Kim loci over number fields" by X. Li and M. Lüdtke (preprint). See the Github repository.

\(L\exists \forall N\)

Lean is a proof assistant, which allows people to write the proof of theorems in a computer programme language. See the website of the Lean community.

A team of me, Huajian Xin, Ella Yu and others attempted to prove the prime number theorem on Lean. See our Github repository. Ella Yu and I gave a talk about this project on a seminar of London Learning Lean held by Imperial College. Watch the recording here. See the slides here.

Numerical Library of Mathematics Algorithm

I made a simple C++ library for numerical algorithms such as solving linear systems, integrals, differential equations and so on numerically. See my Github repository.