Kinetic theory for spatial correlation in nonequilibrium reaction–diffusion systems

A kinetic model of a reaction–diffusion system by which fluctuation around a nonequilibrium steady state can be analyzed without resorting to a local equilibrium assumption is discussed. The spatial correlation function of concentration fluctuations is analytically calculated, and it is shown that (i) the result is consistent with the previous studies for sufficiently slow chemical reactions, and (ii) how the correlation function is modified when chemical reactions are fast.