The goal of the talk is to explain some topological and ergodic properties of the geodesic flow on hyperbolic surfaces. It will follow a pedestrian way and give many examples.

_________

Françoise Dal’Bo is a Professeur des Universités à Rennes (France). She is working on dynamical systems on negatively curved manifolds, in particular on geometrically infinite manifolds. The approach she is developing is related to group theory. Her work looks a bit like a cabinet of curiosities, highlighting surprising phenomena. One of the possible references for the present talk is her book «Geodesic and horocyclic trajectories», Springer-Universitext.