The non-vanishing of bounded cohomology in degree 3
星期五, 22 十一月, 2013 - 11:00
Résumé :
Hyperbolically embedded subgroups have been defined by Dahmani-Guirardel-Osin and they provide a common perspective on several classes of groups including (relatively) hyperbolic groups, mapping class groups, many groups acting on nonpositively curved spaces, etc. The bounded cohomology of a group is defined similarly to the usual cohomology but considering bounded functions only, and is an invariant related to several geometric features of a group like its actions on negatively curved manifolds. I will show how to use the properties of hyperbolically embedded subgroups to get nonvanishing results for the bounded cohomology for the aforementioned groups. Joint with Roberto Frigerio and Maria Beatrice Pozzetti.
Institution de l'orateur :
ETH Zurich
Thème de recherche :
Topologie
Salle :
Salle 4