Notes
These are notes for seminars that I hosted as an undergraduate student at Tsinghua University.

Homotopical Algebra and Homological Algebra (2019).
Notes on $\infty$categories. Chinese version available here. 
Characteristic Classes (2019, in Chinese).
Notes on characteristic classes and the Atiyah–Singer index theorem.
Course projects
Some of the projects that I did for courses contain little pieces of original results, and I post them here.

Homology of Configuration Spaces (2020).
A method to compute the homology of configuration spaces of manifolds. 
Stable Irrationality of Varieties (2020).
Proves the infinitude of stable birational classes in certain families of varieties. 
A Generalised Handle Theory (2018).
Generalises handle theory to noncompact manifolds. This leads to a new proof that $\mathbb{R}^2$ has a unique smooth structure, and more generally, a classification of noncompact surfaces with finite topology.
Notes taken by others
Here are notes of some of my talks that are taken by other people.
 Higher Geometry
(2023, notes by Tommi Muller).
I gave the first two talks, which were an introduction to the theory of algebraic stacks.