For more information about this meeting, contact Nigel Higson, John Roe, Ping Xu, Mathieu Stienon.
|Title:||A new example of a 'natural' C*-algebra for which Ext is not a group|
|Seminar:||Noncommutative Geometry Seminar|
|Speaker:||Jonas Seebach, Aarhus University|
|We recall a sufficient condition for a separable C*-algebra to have non-invertible extensions (by the compact operators on a separable infinite-dimensional Hilbert space). We then outline a proof of the fact that the reduced group C*-algebra of a socalled torus knot group has non-invertible extensions. The proof relies on a deep result by Haagerup and Thorbjørnsen but is otherwise relatively elementary.|
Room Reservation Information
|Date:||11 / 04 / 2010|
|Time:||02:30pm - 03:30pm|