# 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) Alexandros Eskenazis - FSMP et IMJ, Titre Polynomial inequalities on the Hamming cube Date 07/11/2019 Horaire 10:30 à 12:00 Diffusion Résume Every function $f$ on the $n$-dimensional discrete cube $\{-1,1\}^n$ admits a unique representation as a multilinear polynomial of total degree at most $n$, called the Walsh expansion of $f$. We will review the basics of Fourier analysis on the discrete cube and explain a duality argument (inspired by classical work of Figiel) which leads to approximation theoretic estimates for functions whose Walsh coefficients are supported on frequencies bounded above or below. These include Bernstein--Markov type inequalities and their reverses, moment comparison for vector-valued Rademacher chaos of low degree and estimates on the $\ell_p$ sum of influences of bounded functions. The talk is based on joint work with Paata Ivanisvili. Salle salle 13 - couloir 15-16 - 4ème étage Adresse Campus Pierre et Marie Curie