2022/09/26 by Bialy, Misha · 1 citation
#Differential Geometry (math.DG) #Dynamical Systems (math.DS) #FOS: Mathematics
paper · doi:10.48550/arxiv.2209.12743
In this paper we study centrally symmetric Birkhoff billiard tables. We introduce a closed invariant set MB consisting of locally maximizing orbits of the billiard map lying inside the region B bounded by two invariant curves of 4-periodic orbits. We give an effective bound from above on the measure of this invariant set in terms of the isoperimetric defect of the curve. The equality case occurs if and only if the curve is a circle.