# Séminaires : Séminaire Général de Logique

 Equipe(s) : lm, Responsables : S. Anscombe, O. Finkel, A. Khélif, A. Vignati Email des responsables : sylvy.anscombe@imj-prg.fr, vignati@imj-prg.fr Salle : SG 1013 Adresse : Sophie Germain Description

 Orateur(s) Gianluca Basso - Université Lyon I, Titre Topological dynamics beyond Polish groups, and the ambitability question Date 20/09/2021 Horaire 15:15 à 16:15 Diffusion Résume When $G$ is a Polish group, one way of knowing that it has nice dynamics is to show that $M(G)$, the universal minimal flow of $G$, is metrizable. For non-Polish groups, this is not the relevant dividing line: the universal minimal flow of the symmetric group of a set of cardinality $\kappa$ is the space of linear orders on $\kappa$–not a metrizable space, but still nice–, for example. In this talk, we present a set of equivalent properties of topological groups which characterize having nice dynamics. We then concentrate on an open question of Pachl and its consequences on the dynamics of topological groups. This is joint work with Andy Zucker. Salle SG 1013 Adresse Sophie Germain