The many facets of entropy

With our year long visitor Federico Rodriguez-Hertz we are starting a study group on the recent developments on Zimmer's rigidity program, in particular on the works of A. Brown, D. Fisher and S. Hurtado.

These developments are in part the result of many fundamental advances by several people over many years. We plan to review these results, in particular:

• Entropy Theory and Ledrappier-Young works on Pesin's Formula.
• Lyapunov theorem and Pesin manifolds.
• Rudolph's partial solution to Furstenberg conjecture and and Katok-Spatzier measure rigidity theorem.
• Smooth high rank lattice actions and Margulis super-rigidity.
• Non-uniformly hyperbolic Z^d-actions.

We start with an introduction to entropy.