Dynamical decimation renormalization-group technique: Kinetic Gaussian model on nonbranching, branching, and multibranching Koch curves

A generalizing formulation of dynamical real-space renormalization that is appropriate for arbitrary spin systems is suggested. The alternative versio n replaces single-spin flipping Glauber dynamics with single-spin transitio n dynamics. As an application, in this paper we mainly investigate the crit ical slowing down of the Gaussian spin model on three fractal lattices, inc luding nonbranching, branching, and multibranching Koch curves. The dynamic al critical exponent z is calculated for these lattices using an exact deci mation renormalization transformation in the assumption of the magneticlike perturbation, and a universal result z = 1/nu is found.