Abstract
Circles will be characterized by some properties of billiard ball trajectories. The theory of parallels and the parallel axiom play important roles in the geometry of the configuration space. Those characterizations are concerned with Bialy's theorem which is a partial answer to Birkhoff's conjecture.
Citation
Nobuhiro Innami. Shinetsu Tamura. "Circular billiards and parallel axiom in convex billiards." Tsukuba J. Math. 33 (1) 147 - 160, June 2009. https://doi.org/10.21099/tkbjm/1251833211
Information
