TIME-SERIES EXPANSION FOR REACTION PROCESSES

The temporal evolution of reactive systems is studied by means of the exact enumeration of all states of the system for short times. An algo rithm for the evaluation of the power series for the basic quantities of interest is presented. In addition, a consistent method of estimati ng the asymptotic behavior of the series is suggested. This approach i s applied to two reaction schemes, ballistic annihilation and diffusiv e-driven three-species annihilation, where previous Monte Carlo simula tions suggest power-law decays for the concentration. In both cases, r easonable estimates for the decay exponents are obtained.