Sponsored by the Rutgers University Department of Mathematics and the

Center for Discrete Mathematics and Theoretical Computer Science (DIMACS)

**Co-organizers:****Drew Sills**, Rutgers University, asills {at} math [dot] rutgers [dot] edu**Doron Zeilberger**, Rutgers University, zeilberg {at} math [dot] rutgers [dot] edu

Title: Periodic Billiards on an Equilateral Triangle

Speaker: **Andrew Baxter**, Rutgers University

Date: Thursday, February 8, 2007 5:00pm

Location: Hill Center, Room 705, Rutgers University, Busch Campus, Piscataway, NJ

Abstract:

A periodic billiard is a path followed by a ball on a billiards table which retraces itself. The existence of periodic billiards on arbitrary triangles remains an open problem, though many partial results are known. The talk will be divided into two parts. In the first part, I will summarize these partial results, including the recent experimental work of Richard Schwartz. In the second part I will construct, classify, and count all periodic billiards on the equilateral triangle.