Unitarisability of discrete groups (Maria Gerasimova, Dresden)

14.03.2019 13:00

Let G be a discrete group. A group G is called unitarizable if any uniformly bounded representation on any Hilbert space H can be conjugated to a unitary representation. It is well known that amenable groups are unitarizable. It has been open ever since whether amenability characterises unitarisability of groups.
Dixmier: Are all unitarisable groups amenable?
We define the Littlewoon exponent Lit(G) of group G. We will show that, on one hand, Lit(G) is related to unitarisability and amenability and, on other hand, it is related to some geometry of G. We will discuss some examples and applications of this connection.

Lieu

Room 17, Att. jour, date et heure inhabituels, Séminaire "Groupes et Géométrie"

entrée libre