Time: 4:00 p.m.
Location: 114 McAllister Building
Name: Karen Vogtmann
Affiliation: Cornell University
Title: Automorphisms of Free Groups and Outer space
Abstract: The group Out(Fn) of outer automorphisms of a free group can be realized as the group of symmetries of a certain geometric object called Outer space. Invariants of Outer space, and of its quotient by the action of Out(Fn), are often algebraic invariants of the group itself. In this talk I will describe outer space and show how to find non-trivial invariants, which can be described in terms of finite graphs.
