# Séminaires : Séminaire d'Analyse Fonctionnelle

 Equipe(s) : af, 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 Description Le Jeudi à 10h30 -  IMJ-PRG - 4 place Jussieu - 75005 PARIS Lien vers les archives des années antérieures à 2015

 Orateur(s) Yuri Tomilov - Institute of Mathematics, Polish Academy of Sciences, Titre On functional calculi, subordination and related matters Date 10/12/2015 Horaire 10:30 à 12:00 Diffusion Résume Roughly, given a semigroup of probability measures $\mu=\left(\mu_t\right)_$t \ge 0 $and a semigroup of bounded operators $T=\left(T_t\right)_$t \ge 0$ on a Banach space $X$, subordination provides a natural recipe to associate to them a new operator semigroup $T^\mu=\left(T^\mu_t\right)_$t \ge 0\$ on $X$ called a subordinated semigroup. Being an established subject of functional analysis, subordinated semigroups are of importance in e.g. probability and ergodic theories. We will present solutions of several long-standing problems pertaining to the subordination of operator semigroups. The corresponding discrete analogues will also be discussed. Our arguments are based on the interplay between several functional calculi and certain function-theoretical estimates. If time permits, we will explain how a telegram from Besicovitch to Littlewood enters the picture and produces an answer to a question of Erdös et al. originating from the discrete considerations. Salle salle 13 - couloir 15-16 - 4ème étage Adresse Campus Pierre et Marie Curie