Tel-Aviv University
School of Mathematical Sciences
Department Colloquium
Monday, March 8, 2010
Schreiber 006, 12:15
Boris Khesin
University of Toronto
Pseudo-Riemannian geodesics and billiards
Abstract:
In pseudo-Riemannian geometry the spaces of space-like and time-like geodesics
on a pseudo-Riemannian manifold have natural symplectic structures
(just like in the Riemannian case), while the space of light-like geodesics
has a natural contact structure. In the talk I will describe the geometry
of these structures, define pseudo-Euclidean billiards and discuss
their properties.
In particular, I will outline integrability of the null
billiard in the ellipsoid and the null geodesic flow on the ellipsoid
in pseudo-Euclidean space, that is a counterpart of the classical
Poncelet theorem and an example of a contact completely integrable system.

Coffee will be served at 12:00 before the lecture
at Schreiber building 006