KS entropy and mean Lyapunov exponent for coupled map lattices

The statistics of Kolmogorov–Sinai (KS) entropy for a coupled map lattice model are analyzed from the viewpoint of the thermodynamic formalism. It is shown that the fluctuation of KS entropy for a coupled map lattice model satisfies the large deviation statistics. Also, the probability density of Lyapunov exponents (PDLE) is studied and it is shown that the PDLE gives the measure of the irregularity for the spatio-temporal patterns. Mean Lyapunov exponent is introduced and compared with KS entropy.