Flows on the modular surface and trees of fractions

14.07.2022 15:15 - 16:15

Claudio Bonanno (University of Pisa)

Abstract: I will describe a new Poincaré map P_h for the horocycle flow on the modular surface. The map P_h is defined on a section used to define a Poincaré map for the geodesic flow, and in this way both maps turn out to be related to the Stern-Brocot tree of positive rational numbers. This is a classical result for the geodesic flow, but to my knowledge this is the first example of such a connection for the horocycle flow. I will show some of the dynamical properties of the map P_h which can be proved independently from known results for the horocycle flow.
This is based on joint work with A. Del Vigna and S. Isola. 

Organiser:
D. Ravotti
Location:

BZ 9, 9. OG, OMP1