Geometry, Topology and Dynamics Seminar
Rostyslav Kravchenko
University of Chicago
Invariant and strongly invariant random subgroups
Abstract: The notion of an IRS (invariant random subgroup) provides a natural probabilistic counterpart of the notion of normal subgroup. It has been defined recently by M. Abert, Y. Glasner and B. Virag.
In this talk we will first recall its definition, properties and applications. Then we describe a new notion of a random subgroup which is strongly invariant with respect to all group automorphisms (we call them strongly invariant subgroups, SIRS).
We produce a series of nontrivial examples of SIRS, in particular construct an uncountable family of SIRS on the free group F_n. We show an application to a construction of continuous ergodic IRSs.
This is a joint work with L. Bowen and R. Grigorchuk.
Wednesday November 6, 2013 at 3:00 PM in SEO 612