1–2 déc. 2022
Le Bois-Marie
Fuseau horaire Europe/Paris

Propriétés de relèvement pour les $C^*$-algèbres : du local au global ?

1 déc. 2022, 09:30
1h
Centre de conférences Marilyn et James Simons (Le Bois-Marie)

Centre de conférences Marilyn et James Simons

Le Bois-Marie

35, route de Chartres 91440 Bures-sur-Yvette

Orateur

Prof. Gilles PISIER (Sorbonne Université - Texas A&M University)

Description

The main problem we will consider is whether the local lifting property (LLP) of a $C^*$-algebra implies the (global) lifting property (LP). Kirchberg showed that this holds if the Connes embedding problem has a positive solution, but it might hold even if its solution is negative. We will present several new characterizations of the lifting property for a $C^*$-algebra $A$ in terms of the maximal tensor product of A with the (full) $C^*$-algebra of the free group ${\mathbb F}_{\infty}$. We will recall our recent construction of a non-exact $C^*$-algebra with both LLP and WEP. This prompted us to try to prove that LLP implies LP for a WEP $C^*$-algebra. While our investigation is not conclusive we obtain a fairly simple condition in terms of tensor products that is equivalent to the validity of the latter implication.

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