English

Dan Reznik's identities and more

Differential Geometry 2020-05-06 v2 Dynamical Systems

Abstract

Dan Reznik found, by computer experimentation, a number of conserved quantities associated with periodic billiard trajectories in ellipses. We prove some of his observations using a non-standard generating function for the billiard ball map. In this way, we also obtain some identities valid for all smooth convex billiard tables.

Keywords

Cite

@article{arxiv.2001.08469,
  title  = {Dan Reznik's identities and more},
  author = {Misha Bialy and Serge Tabachnikov},
  journal= {arXiv preprint arXiv:2001.08469},
  year   = {2020}
}

Comments

This is an extended version

R2 v1 2026-06-23T13:18:38.855Z