Announcements
20 May 2013, 10:15-12:00EXTENDED QUOTIENT
Let G be a group acting on a set X. The quotient X/G is obtained be collapsing each orbit to a point. The extended quotient, denoted by X//G, is obtained by replacing each orbit by the set of conjugacy classes of the isotropy group of any point in the orbit. The extended quotient of the second kind, denoted by (X//G)_2, is obtained by replacing each orbit by the set of (equivalence classes of) irreducible representations of the isotropy group of any point in the orbit. This talk will explore some applications of extended quotients. The applications are to equivariant Chern character and to representation theory of Lie groups and p-adic groups. In representation theory, the issue is how to "lift" the Baum-Connes conjecture from K-theory to representation theory.
PAUL F. BAUM (Pennsylvania State University, State College, USA / IMPAN)
20 May 2013, 14:15-16:00
C*-QUANTUM GROUPS WITH PROJECTION
C*-quantum groups with projection are the quantum-group analogue of semidirect products of groups. In parallel to a theorem by Radford for Hopf algebras with projection, we describe a C*-quantum group with projection using a quantum group in a braided tensor category of coactions of a certain quasitriangular C*-quantum group. (Joint work in progress with Ralf Meyer and Stanislaw Lech Woronowicz.)
SUTANU ROY (Universitat Goettingen)