Geometry & Topology Seminar: "Order complexes of coset posets of finite groups are not contractible"

John Shareshian, Washington University in Saint Louis

Abstract: I will discuss joint work with Russ Woodroofe, in which we use Smith Theory and the Classification of Finite Simple Groups to prove that the order complex of the partially ordered set of all cosets of all proper subgroups of an arbitrary finite group is not acyclic in characteristic two, and therefore not contractible.

Host: Xiang Tang