Anchors of irreducible characters

Abstract

Given a prime number p, every irreducible character χ of a finite group G determines a unique conjugacy class of p-subgroups of G which we will call the anchors of χ. This invariant has been considered by Barker in the context of finite p-solvable groups. Besides proving some basic properties of these anchors, we investigate the relation to other p-groups which can be attached to irreducible characters, such as defect groups, vertices in the sense of J. A. Green and vertices in the sense of G. Navarro.