Speaker:	Martin Bridson (University of Oxford & Clay Math Institute)
Title:	Commensurator rigidity for automorphism groups of free groups
Abstract:	The natural map from Aut(\( F_n \)) to its abstract commensurator is an isomorphism if \( n \) is at least \( 3 \), and the image is a subgroup of finite index if \( n=2 \). The proof relies, among other things, on an understanding of the ways in which a direct product of free groups can be embedded in Aut(\( F_n \)). This is joint work with Ric Wade.