Calculation of dynamic critical properties from a cluster-reaction theory

Critical fluctuations in kinetic Ising models are interpreted in terms of cluster reactions. The basic assumption, that clusters with l spins grow at a rate lr, is tested by Monte Carlo computations in the single-spin-flip case. The dynamic susceptibilities associated with order parameter and energy are then calculated also for nonzero magnetic field, and are shown to fulfill dynamic scaling. The exponent (2-r)βδ of the relaxation times can be different from the susceptibility exponent γ. © 1974 The American Physical Society.