MATHEMATICS COLLOQUIUM - Yoshikata Kida (Kyoto University)

Speaker: 
Yoshikata Kida (Kyoto University)
Topic: 
Orbit Equivalence Relations Arising From Baumslag-Solitar Groups

Abstract: This talk is about measure-preserving actions of countable groups on probability measure spaces and their orbit structure. Two such actions are called orbit equivalent if there exists an isomorphism between the spaces preserving orbits. In this talk, I focus on actions of Baumslag-Solitar groups that have two generators, a and t, with the relation ta^p=a^qt, where p and q are given integers. This group is well studied in combinatorial and geometric group theory. Whether Baumslag-Solitar groups with different p and q can have orbit-equivalent actions is still a big open problem. I will discuss invariants under orbit equivalence, motivating background and some results toward this open problem.

Event Date: 
April 16, 2015 - 3:30pm to 4:30pm
Location: 
213 MLH
Host: 
Ionut Chifan
Calendar Category: 
Colloquium