Entropy, Lyapunov exponents, and mean free path for billiards
The author reviews known results and derives some new ones about the mean free path, Kolmogorov-Sinai entropy, and Lyapunov exponents for billiard-type dynamical systems. The author focusses on exact and asymptotic formulas for these quantities. The dynamical systems which are considered in this paper include the periodic Lorentz gas, the stadium and its modifications, and the gas of hard balls. Some open questions and numerical observations are discussed.
scientific article; zbMATH DE number 1279678
scientific article