An introduction to the Kechris-Pestov-Todorčević correspondence

17 ottobre 2022
Orario di inizio 
PovoZero - Via Sommarive 14, Povo (Trento)
Aula seminari di Fisica
Comunità universitaria
Online su prenotazione
Email per prenotazione: 

“Doc in Progress” is pleased to introduce you to:

  • Alessandro Codenotti - PhD in Mathematics - University of Münster

A topological group G is said to be extremely amenable if it satisfies the strongest possible fixed point property: whenever G acts continuously on a compact topological space, there must be a fixed point. In this talk we will present an elementary proof, due to Pestov, of the extreme amenability of Aut(ℚ, ≤), the group of order preserving functions on the rationals. This is the simplest manifestation of a widespread phenomenon, now known as the Kechris-Pestov-Todorčević correspondence or KPT correspondence in short,  which links together topological dynamics, Ramsey theory and the model theory of homogeneous structures.