Microscopic chaos and chemical reactions

Microscopic chaos is the dynamical randomness in the collisional motion of atoms and molecules in fluids. This chaos animates different mesoscopic stochastic phenomena and, in particular, the reaction-diffusion processes. For different chemical reactions, we show how the reaction rate can be related to the characteristic quantities of chaos like the Lyapunov exponents and the Kolmogorov-Sinai entropy which are associated with a fractal repeller. In spatially extended deterministic chaotic systems, chemio-hydrodynamic modes with exponential decay are shown to exist as Schwartz-type distributions associated with Pollicott-Ruelle resonances. The problem of entropy production is also discussed.