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) Roman Sauer - Karlsruhe Institute of Technology,
Titre Action on Cantor spaces and macroscopic scalar curvature
Horaire14:00 à 15:00
Diffusion https://bigbluebutton3.imj-prg.fr/b/fra-j6k-9fw
RésumeWe prove the macroscopic cousins of three conjectures: 1) a conjectural bound of the simplicial volume of a Riemannian manifold in the presence of a lower scalar curvature bound, 2) the conjecture that rationally essential manifolds do not admit metrics of positive scalar curvature, 3) a conjectural bound of l2-Betti numbers of aspherical Riemannian manifolds in the presence of a lower scalar curvature bound. The macroscopic cousin is the statement one obtains by replacing a lower scalar curvature bound by an upper bound on the volumes of $1$-balls in the universal cover. Group actions on Cantor spaces surprisingly play an important role in the proof. The talk is based on joint work with Sabine Braun.
AdresseSophie Germain