MIGDAL-TYPE RENORMALIZATION-GROUP CALCULATION FOR THE KINETIC ISING-MODEL

We make use of the calculation of Achiam and Kosterlitz and investigate the generalization of the Migdal-type renormalization-group calculation to critical dynamics, by looking at the one- and two-dimensional kinetic Ising model with no conserved magnetization. In the two-dimensional case the dynamical critical index ZM (magnetic perturbation) =2.064 and ZE (energylike perturbation) =1.819 for scale factor =1. ZM involves the static exponent, while ZE involves 1, and therefore, it is not surprising that ZM is closer to the high-temperature expansion results, since in the Migdal approximation for statics is much closer to the exact value than 1. In one dimension we obtain ZM=ZE=2, which is the exact result of Glauber. © 1979 The American Physical Society.