Tuesdays at 3:30pm-4:30pm in CH (Cockins Hall) 240 or as announced
Previous Quarters: Fall 2009
Tuesday, January 5, 2010 |
| Speaker: David Dumas (University of Illinois at Chicago) |
| Location: CH 240 |
| Time: 3:30pm |
Tuesday, January 26, 2010 |
| Speaker: John Maginnis (Ohio State University) |
| Title: Fixed Point Sets and Lefschetz Modules for Subgroup Complexes |
| Location: CH 240 |
| Time: 3:30pm |
| Abstract: (joint work with Silvia Onofrei) The best known reduced Lefschetz module is the Steinberg module for a finite Chevalley group acting on its Tits building, an irreducible and projective module. The reduced Lefschetz module for a finite group G acting on its Brown complex (simplices are given by chains of p-subgroups) is always projective. We study another subgroup complex, using p-subgroups which contain in their centers an element lying in the center of a Sylow p-subgroup of G. We have theorems concerning fixed point sets of elements of order p acting on these simplicial complexes, and we apply results of Robinson and others to determine information about indecomposable summands of the reduced Lefschetz module (vertices and defect groups of their blocks). We have many specific computations for sporadic simple groups, some of them determined using the GAP package. |
Tuesday, February 2, 2010 |
| Speaker: François Labourie (Orsay University) |
| Title: Proper actions of a free group on the affine space and the geodesic flow (joint with Goldman and Margulis) |
| Location: CH 240 |
| Time: 3:30pm |
Tuesday, February 9, 2010 |
| Speaker: Christophe Pittet (CMI University of Aix-Marseille I) |
| Location: CH 240 |
| Time: 3:30pm |
Tuesday, February 16, 2010 |
| Speaker: Nicolau Saldanha (PUC Rio de Janeiro) |
| Location: CH 240 |
| Time: 3:30pm |