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 |
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| Seminar: | Noncommutative Geometry Seminar |
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| Speaker: | Jonas Seebach, Aarhus University |
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| Abstract: |
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| 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
| Room Number: | MB106 |
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| Date: | 11 / 04 / 2010 |
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| Time: | 02:30pm - 03:30pm |
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