Mathematics is created to understand the world around us
Research interests
I study phenomena in theoretical physics using rigorous mathematics. In particular, I'm trying to understand topological phases of matter and quantum field theory (QFT). I like to have a broad scope, both in mathematics and physics. My main focus during my PhD lies in understanding unitary topological field theories (TFT). I am also interested in symmetry-protected topological (SPT) phases.
My favorite way to describe QFT is by functorial quantum field theory. This framework was originally developed by Graeme Segal for conformal field theory and Michael Atiyah for topological field theory, but has since been generalized in multiple directions. In particular, functorial QFTs for metric-dependent theories have been defined by Stephan Stolz and my advisor Peter Teichner. Field theories that are invertible under tensor product (stacking) are called invertible. Invertible topological field theories are well-understood mathematically and provide a great tool to study SPT phases, as emphasized by Freed & Hopkins. Namely, the low energy effective field theory of (the continuum limit of) a QFT describing an invertible phase is often an invertible topological field theory.
Research talks
Invited talk at ICTP on invertible field theory with fermionic symmetry
Notes of several talks:
Two-dimensional topological field theory, spin-statistics and reflection structures
Two-dimensional topological field theory and spin-statistics
Symmetry-protected topological phases in the Bogliubov-de-Gennes framework
Free fermion symmetries and particle-hole reversal
Selected work
Master thesis "K-theory classifications of symmetry-protected topological phases of matter" (updated 13-06-2021)
Talks in learning seminars
The following is a collection of informal notes from several talks I gave in learning seminars. Feel free to send me questions or corrections.
Differential cohomology theories as sheaves of spectra on the site of manifolds
Morita equivalences of Lie groupoids
Symmetric monoidal infinity categories
Functional analysis for factorization algebras: differentiable vector spaces