title: Billiard dynamics: an updated survey with the emphasis on open problems.
abstract: This is an updated and expanded version of our earlier survey article [E. Gutkin, "Billiard dynamics: a survey with the emphasis on open problems," Regular Chaotic Dyn. 8, 1-13 (2003)]. Section I introduces the subject matter. Sections II s3 s4 expose the basic material following the paradigm of elliptic, hyperbolic, and parabolic billiard dynamics. In Sec. V, we report on the recent work pertaining to the problems and conjectures exposed in the survey [E. Gutkin, "Billiard dynamics: a survey with the emphasis on open problems," Regular Chaotic Dyn. 8, 1-13 (2003)]. Besides, in Sec. V we formulate a few additional problems and conjectures. The bibliography has been updated and considerably expanded.
authors: Nicolaus Copernicus University, Chopina 12/18, Torun 87-100, Poland and IM PAN, Sniadeckich 8, Warszawa 10, Poland. gutkin@mat.umk.pl
authors: Eugene
authors: E
authors: Gutkin