Gil Bor, Cusps of Caustics by Reflection in a Convex Billiard Table
B236-1 IBS, Korea, Republic ofSpeaker Gil Bor CIMAT Place a point light source inside a smooth convex billiard table (or mirror). The n-th caustic by reflection is the envelope of light rays after n reflections. Theorem: each of these caustics, for a generic point light source, has at least 4 cusps. Conjecture: there are exactly 4 cusps …