# Chi Ho Yuen:Filtrations of tope spaces of oriented matroids

**Time: **
Wed 2022-11-23 10.15 - 11.15

**Location: **
KTH 3721

**Video link: **
Meeting ID: 637 4378 6038

**Participating: **
Chi Ho Yuen (University of Oslo)

Abstract: Oriented matroids are matroids with extra sign data, and they arise naturally in the study of real hyperplane arrangements. In order to study the topology of real algebraic/tropical hypersurfaces constructed from patchworking, Renaudineau and Shaw introduced an algebraically defined filtration of the tope spaces of oriented matroids based on Quillen filtration, We will prove the equivalence of their filtration and the topologically defined Kalinin filtration, as well as the combinatorially defined Gelfand-Varchenko dual degree filtration. If time permits, we will also discuss a potential globalization. This is joint work with Kris Shaw.

If you plan to attend online, please contact Petter Restadh (petterre AT kth DOT se) for the password.