Brandeis University Everyperson Seminar

Monday March 21, 2005, 4 PM, Goldsmith 317

tea at 3:30 PM at the Math Department lounge (Goldsmith 300)

Speaker: Herbert Abels (University of Bielefeld)

Title: Crystallographic and properly discontinuous affine groups

Abstract: In the talk the structure of properly discontinuous affine groups and in particular affine crystallographic groups will be discussed. They are the fundamental groups of complete affine flat manifolds. One of the main open problems is Auslander's conjecture. It claims that every affine crystallographic group is virtually solvable. This is not true for the more general case of properly discontinuous affine groups. In the talk the geometry and dynamics behind this fact and in particular Margulis' invariant will be explained.