Séminaires : Séminaire d'Algèbres d'Opérateurs

Equipe(s) : ao,
Responsables :Pierre Fima, François Le Maître, Romain Tessera
Email des responsables :
Salle : 2015
Adresse :Sophie Germain

Orateur(s) Stefaan Vaes - KU Leuven,
Titre Nonsingular Bernoulli actions of arbitrary type
Horaire14:00 à 15:00
Diffusion https://bigbluebutton3.imj-prg.fr/b/fra-j6k-9fw
RésumeI will survey several recent results on the ergodicity and possible Krieger types of nonsingular Bernoulli actions. Given a countable group G and a base space X, consider the Bernoulli shift action of G on X^G, together with the product measure of a family of probability measures \mu_g on X. Even the basic question of ergodicity of this action turns out to be subtle. I will present general criteria to determine the Krieger type and show that all types, including II_\infty and III_0, can arise from nonsingular Bernoulli actions of amenable groups.
AdresseSophie Germain