Chris’ website

I am a postdoc at the GEOTOP centre within the University of Copenhagen since October 2025. I’m interested in geometric representation theory, algebraic geometry, and the representation theory of finite groups.

To contact me, please use christopher(dot)t(dot)hone(at)gmail(dot)com.

Papers:

1. Torsion primes for spaces of commuting elements in Lie groups(2026), joint with Simon Gritschacher.
2. Real algebraic varieties and their intersection cohomology(2026)
3. The geometry of tilting composition series via Richardson varieties(2026), joint with Joe Baine.
4. Semisimplifying categorical Heisenberg actions and periodic equivalences(2025), joint with Finn Klein, Bregje Pauwels, Alexander Sherman, Oded Yacobi, Victor L. Zhang.
5. Geometric extensions(2023), joint with Geordie Williamson.

Papers in preparation:

1. Mod two perverse sheaves on the real affine Grassmannian in type A. This is using real geometric extensions to describe the tensor category of perverse sheaves on the real affine Grassmannian. The main result is the construction of a fully faithful exact monoidal functor from the mod two algebraic representations of the general linear group to this category of real perverse sheaves.

2. Equivariant topological K theory at an automorphism. Given a finite group G with automorphism s, one has an s-invariant character ring, a free module over the cyclotomic integers with orthonormal basis the s-invariant irreducible reps of G (eg, Glauberman correspondence). In this work I construct a 2-periodic fully commutative genuine equivariant ring spectrum which recovers this Mackey functor as its homotopy groups, with Chern character recovering the twisted character map of the s-invariant characters.

Other stuff:

My PhD thesis.

The third chapter of my thesis deals with coherence problems in a six functor formalism, introducing a diagrammatic framework for analysing these. The user guide section explains how this works in a model independent way. I’ve vibe coded a basic website to do some of this automatically. In its current state it is best for playing with the examples to demonstrate the diagrammatics.

Geordie Williamson and I ran a modular rep theory course Semester 1 2023. The website can be be found here, as can recordings and notes for most lectures.

My undergrad Honours thesis. It covers some aspects of one dimensional algebraic geometry.