## Dynamics, Geometry, & Groups Seminar

### Tuesday, August 27th, 2019

**Time:** 1:30 p.m** Place:** Jeffery Hall 319

**Speaker:** Catherine Pfaff (Queen's University)

**Title:** Typical Trees: An Out(F_r) Excursion.

**Abstract:** Random walks are not new to geometric group theory (see, for example, work of Furstenberg, Kaimonovich, Masur). However, following independent proofs by Maher and Rivin that pseudo-Anosovs are generic within mapping class groups, and then new techniques developed by Maher-Tiozzo, Sisto, and others, the field has seen in the past decade a veritable explosion of results. In a 2 paper series, we answer with fine detail a question posed by Handel-Mosher asking about invariants of generic outer automorphisms of free groups and then a question posed by Bestvina as to properties of R-trees of full measure in the boundary of Culler-Vogtmann outer space. This is joint work with Ilya Kapovich, Joseph Maher, and Samuel J. Taylor.