Office 419, Mathematisches Institut
79104 Freiburg im Breisgau, Germany
I am a Research Assistant (of Prof. Wolfgang Soergel) at the University of Freiburg.
Before this, I was a PostDoc at MSRI, Berkeley, during the semester Group Representation Theory and Applications.
I completed my PhD in January 2018 at the Max Planck Institute, Bonn,
under the supervision of Geordie Williamson.
Here you can find my PhD thesis: Hodge theoretic aspects of Soergel bimodules and representation theory.
Tutor for the seminar Reflection groups (Spiegelungsgruppen).
My research area is called Geometric Representation Theory. I enjoy thinking primarily about aspects of representation theory that can be "seen" geometrically.
I am particularly interested in the following topic:
- Hecke algebras and their categorification via Soergel bimodules
- Kazhdan-Lusztig Combinatorics
- Perverse sheaves
- Hodge Theory
- Flag manifolds and the geometry of Schubert varieties
- Koszul Duality
- Affine Grassmannians and Geometric Satake Correspondence
- Quantum groups and KLR algebras
- Nilpotent Orbits and Springer Correspondence
- Representations of Algebraic Groups
- A Schubert basis for the interesction cohomology of Grassmannians (In preparation)
- A combinatorial formula for the coefficient of q of Kazhdan-Lusztig polynomials
We study the coefficient of q in Kazhdan-Lusztig polynomials. Using moment graphs, for finite groups of type ADE we prove that this coefficient can be
computed via a formula which only depends on the poset structure of the Bruhat interval.
- The Néron-Severi Lie Algebra of a Soergel module
To appear in Transformation Groups
Following Looijenga and Lunts, we introduce for any Soergel module a semisimple Lie algebra generated by all the Lefschetz operators and their adjoints.
This algebra, called the Néron-Severi Lie algebra, can be used to provide a simple proof of the well-known fact that a Schubert variety is
rationally smooth if and only if its Betti numbers satisfy Poincaré duality.
We also determine a large set of elements, for finite Coxeter group, where the Neron-Severi Lie algebra coincides with the full Lie algebra
of endomorphism preserving the intersection form.
- The Hard Lefschetz Theorem in positive characteristic for the Flag Varieties
To appear in International Mathematical Research Notices
We show that the Hard Lefschetz theorem holds for the flag variety of some reductive group in characteristic p, if p is larger than the number of positive roots.
The converse also holds, a part from 3 exceptional cases. One can also deduce an algebraic proof of the Hard Lefschetz theorem in the already known
characteristic 0 case.
You should also visit Thorge Jensen's webpage! He was also a student of Geordie Williamson.