# Calendar

Topology/Geometry Seminar

## Torsion invariants of complexes of groups

#### Kevin Schreve (Louisiana State)

Location:  Zoom
Date & time: Tuesday, 26 October 2021 at 11:00AM - 12:00PM

Abstract:  For a residually finite group G, one can consider various homological growths of a chain of finite index normal subgroups of G. We will be most interested in the growth of torsion in integral homology. The groups we consider all act on contractible complexes with strict fundamental domain Q, where stabilizers are either trivial or have vanishing torsion growth. We then show the torsion homology of the subcomplex of Q consisting of cells with nontrivial stabilizer completely determines the torsion growth of G. For example, we give an exact calculation of these invariants for right-angled Artin groups. This is joint work with Boris Okun, and I will mention earlier work with Grigori Avramidi and Boris Okun.