Christopher Perez : Splittings of groups and actions on trees

Posted by Gregory Taylor , part of the Graduate Student Colloquium.

At

Feb. 20, 2019, 5 p.m.

In

636 SEO

Abstract

Infinite groups can be studied by looking at how they split, i.e. how they can be expressed as amalgamated free products and HNN extensions, and more generally as graphs of groups. Splittings arise in a very geometric way when considering fundamental groups of spaces, and they can be found by studying how groups act on trees. In this talk we will give an overview of Bass-Serre theory and briefly discuss some applications in group theory, geometry and topology, and logic.