Crooked Geometry

Jeudi 22 mars 2012 14:00-15:00 - Bill Goldman - Maryland

Résumé : In the late 1970’s Margulis showed that nonabelian free groups G could act properly discontinuously on R3 by affine transformations, answering a question raised by Milnor. The quotients are geodesically complete flat Lorentzian 3-manifolds with fundamental group G. To understand their geometry, Todd Drumm introduced polyhedra called crooked planes to build fundamental domains.In this talk I will describe how the resulting synthetic geometry leads to a classification of the first nontrivial cases, namely when G has rank two. This is joint work with Charette and Drumm.

Lieu : bât. 425 - 121-123

Crooked Geometry  Version PDF