# Linear Representations of the Automorphism Group of a Free Group

 LIE GROUPS, REPRESENTATIONS AND DISCRETE MATH Topic: Linear Representations of the Automorphism Group of a Free Group Speaker: Fritz Grunewald Affiliation: IAS Date: Tuesday, March 21 Time/Room: 2:10pm - 3:10pm/S-101

This talk is about joint work with A. Lubotzky. Let $F_n$ be the free group on $n\ge 2$ elements and $\A(F_n)$ its group of automorphisms. We have contructed new linear representations of $\A(F_n)$ arising through the action of finite index subgroups of it on relation modules of finite quotient groups of $F_n$. We show (under certain conditions) that the images of our representations are arithmetic groups.