Title：Haagerup property of semigroup crossed products

Abstract:In this report, we focus on the Haagerup  property of semigroup  crossed products for lattice ordered groups. Let (G,G+) be a lattice ordered group. We show that the reduced semigroup C*-algebra has  the Haagerup property if and only if G has the Haagerup property. Assume that G acts on a unital C*-algebra A through an action α. We show that if the reduced semigroup crossed product has the Haagerup property, then both A and G have the Haagerup  property. On the other hand, it is shown that if (G,G+) is s-amenable and A has the Haagerup property, then the reduced semigroup crossed product has the Haagerup property.

Speaker：Qing Meng，Qufu Normal University

Date：2:30pm-5:30pm 2021-12-13（Monday）.

Tencent Meeting ID： 576-251-781

Organizer：School of Mathematical Science

Students and teachers who are interested in functional analysis are welcome.