### Wild Rose, Narcissus and other Elliptic Flowers: a new class of billiards with surprising properties.

- Series
- Geometry Topology Seminar
- Time
- Monday, October 31, 2022 - 14:00 for 1 hour (actually 50 minutes)
- Location
- Skiles 006
- Speaker
- Leonid Bunimovich – Georgia Tech

I'll talk about some 2D billiards, the most visual class of dynamical systems, where orbits (rays) move along straight lines within a billiard table with elastic reflections off the boundary. Elliptic flowers are built “around" convex polygons, and the boundary of corresponding billiard tables consists of the arcs of ellipses. It will be explained why some classes of such elliptic flowers demonstrate a never expected before dynamics, and why it raises a variety of (seemingly new) questions in geometry (particularly in 3D), in bifurcation theory (particularly about singularities of wave fronts and creation of wave trains), in statistical mechanics, quantum chaos, and perhaps some more. The talk will be concluded by showing a free movie. Everything (including various definitions of ellipses) will be explained/reminded.