# Sparse graphs, topological dynamics and structural Ramsey theory

**Date**: Wednesday 15 March 2017, 16:00 – 17:30**Location**: Mathematics Level 8, MALL 1 & 2, School of Mathematics**Type**: Pure Mathematics seminars, Seminar series, Logic seminars**Cost**: Free

#### David Evans, Imperial College London. Part of the logic seminar series.

I will consider automorphism groups of countable structures acting continuously on compact spaces: the viewpoint of topological dynamics. A beautiful paper of Kechris, Pestov and Todorcevic makes a connection between this and the 'structural Ramsey theory' of Nesetril, Rodl and others infinite combinatorics. I will describe some results and questions in the area and say how some 'sparse' graphs constructed by Hrushovski to answer a variety of questions in model theory provide answers to some of these questions (but then raise more questions).

This is joint work with Hubicka and Nesetril.

**David Evans,** *Imperial College London*