L-amenable actions (Vadim Kaimanovich, University of Ottawa)

28.02.2017 10:30

The notion of amenability was first extended from groups to transitive group actions by Greenleaf (1969) by requiring that there exist an invariant mean on the action space. However, shortly thereafter this notion was eclipsed by Zimmer's definition (which is in a sense complementary to Greenleaf's one) and remained almost forgotten until fairly recently.

Amenability of a transitive action of a finitely generated group is equivalent to amenability of the associated Schreier graph, and the growing interest in properties of Schreier graphs has made Greenleaf's definition popular again during the last decade.

Inspired by a recent paper by Juschenko and Zheng on the Liouville property for Schreier graphs, I will introduce yet another version of amenability for actions and discuss its basic properties.

Lieu

Room 623, Séminaire "Groupes et Géométrie"

Organisé par

Section de mathématiques

entrée libre

Classement

Catégorie: Séminaire