Videos

Anosov representations and proper actions

Presenter
April 14, 2015
Keywords:
  • quotient manifolds
  • discrete subgroups
  • orthogonal and unitary groups of non-definite signature
  • Lorentz group
  • Cartan decomposition
  • proper actions
  • parabolic subgroup
MSC:
  • 37D20
  • 37Dxx
  • 37-xx
  • 20F67
  • 20Fxx
  • 20F65
Abstract
Anosov representations of word hyperbolic groups into reductive Lie groups provide a generalization of convex cocompact representations to higher real rank. I will explain how these representations can be used to construct properly discontinuous actions on homogeneous spaces. For a rank-one simple group G, this construction covers all proper actions on G, by left and right multiplication, of quasi-isometrically embedded discrete subgroups of G×G; in particular, such actions remain proper after small deformations, and we can describe them explicitly. This is joint work with F. Guéritaud, O. Guichard, and A. Wienhard.
Supplementary Materials