4:00 pm Thursday, April 21, 2011
Colloquium: Global Rigidity for certain actions of higher rank lattices on the torus
by Federico Rodriguez Hertz (Penn State) in HB 227
In this talk we will give an approach to the following theorem: Let $\Gamma$ be an irreducible lattice in a connected semi-simple Lie group with finite center, no non-trivial compact factor and of rank bigger than one. Let $a:\Gamma \to Diff(T^N)$ be a real analytic action on the torus preserving an ergodic large measure (large means essentially that its support is non trivial in homotopy). $a$ induces a representation $a_0:\Gamma \to SL(N,Z)$. Assume further that $a_0$ has no zero weight and no rank one factor. Then $a$ and $a_0$ are conjugated by a real analytic map outside a finite $a_0$ invariant set. The theorem essentially says that nonlinear action $a$ is built from linear $a_0$ by blowing up finitely many point. This is joint work with A. Gorodnik, B. Kalinin and A. Katok. Host Department: Rice University-Mathematics Submitted by dani@rice.edu |