Rigidity of Anosov Zd actions on nilmanifolds

David Fisher (Indiana University and Radcliffe Institute for Advanced Studies, Harvard)

Abstract: It is conjectured by Katok and Spatzier that all "irreducible" Anosov Zd actions on manifolds are conjugate to affine algebraic actions on nilmanifolds. I will discuss motivation and prior work on the subject before concentrating on recent joint work with Kalinin and Spatzier.
There is a strong analogy between global rigidity results of this kind and work on rigidity of invariant measures. I will try to explain some of this analogy and point out how our work is analogous to ideas of Lindenstrauss that led to breakthroughs work on measure rigidity.