Monte Carlo computation of correlation times of independent relaxation modes at criticality

We investigate aspects of the universality of Glauber critical dynamics in two dimensions. We compute the critical exponent z and numerically corrobor ate its universality for three different models in the static Ising univers ality class and for five independent relaxation modes. We also present evid ence for universality of amplitude ratios, which shows that, as far as dyna mic behavior is concerned, each model in a given universality class is char acterized by a single nonuniversal metric factor which determines the overa ll time scale. This paper also discusses in detail the variational and proj ection methods that are used to compute relaxation times with high accuracy .