Amenable groups are small from a large scale geometric point of view. If a space can be covered by few subsets with amenable fundamental group, there are strong vanishing results for several invariants: simplicial volume, L^2-Betti numbers, and homology growth. We study the minimal number of such subsets needed to cover a space, the so-called amenable category. In the talk, we focus on aspherical spaces and compute this number for right-angled Artin groups. 

Il seminario si terrà presso l'aula Russo (Palazzo della Carovana). Per maggiori informazioni visitare il sito http://people.dm.unipi.it/babygeometri/index.html