Universality classes for one dimensional kinetic Ising models

Abstract

We use variational techniques to construct upper and lower bounds for the dynamical exponentz of kinetic Ising models. The most important universality class is shown to havez=2. We find larger values ofz, however, for continuous sets of both pure single-spin-flip and double-spin-flip models. For pure double-spin flips with order parameter conservation we findz≧5; this bound is consistent with a corresponding transport coefficient which vanishes at the zero-temperature critical point.