Automorphisms of Free Groups and Outer space


Karen Vogtmann

Cornell University

Brandeis University

Thursday, March 31, 2005


Talk at 4:30 p.m. in 317 Goldsmith Hall

Tea at 4:00 p.m. in 300 Goldsmith Hall


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.



Home Web page:  Maxim Braverman Posted: March 16, 2005