Louise Hay Logic Seminar
Sam Ziegler & Phil Wesolek
UIC
Weak Equivalence / Conjugacy classes in locally compact subgroups of S_{\infty}
Abstract: Sam will speak about the relation of weak equivalence between actions of discrete groups on the interval [0,1],
in particular the non-classifiability of this relation.
Phil will speak about the following: many closed subgroups of S_{\infty} admit a comeagre conjugacy class. For example, S_{\infty} (folklore)
or Aut(\mathbb{Q},<) (Truss) admit a comeagre conjugacy class. Kechris and Rosendal ask if a locally compact
subgroup of S_{\infty} can admit a comeagre conjugacy class. We answer the question in the negative via an
analysis of locally compact subgroups of S_{\infty} with topological conditions on a conjugacy class.
Thursday September 19, 2013 at 4:00 PM in SEO 427