PSU Mark
Eberly College of Science Mathematics Department

Meeting Details

For more information about this meeting, contact Sergei Tabachnikov.

Title:Outer billiards, kites, and the modular group
Seminar:Department of Mathematics Colloquium
Speaker:Richard Schwartz, Brown University
Outer billiards is a basic dynamical system defined relative to a convex planar shape. Since its introduction in the 1950s, one of the central questions has been whether or not there exists a shape for which there are unbounded orbits. I will give a visual demonstration of my recent result that outer billiards has unbounded orbits when defined relative to every so-called irrational kite. It turns out that there is a close connection between outer billiards on kites and the modular group. This connection leads to a very good understanding of the dynamics of the system, and also to some beautiful computer pictures.

Room Reservation Information

Room Number:MB114
Date:10 / 02 / 2008
Time:04:00pm - 05:00pm