|Responsables :||E. Abakoumov - D. Cordero-Erausquin - G. Godefroy - O. Guédon - B. Maurey - G.Pisier|
|Email des responsables :|
|Salle :||salle 13 - couloir 15-16 - 4ème étage|
|Adresse :||Campus Pierre et Marie Curie|
Le Jeudi à 10h30 - IMJ-PRG - 4 place Jussieu - 75005 PARIS
|Orateur(s)||Vadim Kaimanovich - University of Ottawa,|
|Titre||Amenability, approximate invariance and the Liouville property|
|Horaire||10:30 à 14:16|
|Résume||The class of amenable groups was introduced by von Neumann in 1929 to explain the Hausdorff-Banach-Tarski paradox. This original definition was given in highly non-constructive terms of invariant means. A much more constructive characterization of amenability in terms of approximately invariant measures was only given in the 1950s by Day (although the phenomenon was definitely known much earlier). Both of them are also closely related to the Liouville property, i.e., to the absence of non-constant bounded harmonic functions.
I will overview the historical background and outline a number of new results on the amenability beyond the group setting.
|Salle||salle 13 - couloir 15-16 - 4ème étage|
|Adresse||Campus Pierre et Marie Curie|