UNIVERSAL DYNAMICS OF INDEPENDENT CRITICAL RELAXATION MODES

We obtain the relaxation times of several, progressively rapid, indepe ndent modes of three models in a two-dimensional Ising universality cl ass. Their size dependence can be described by one single dynamic expo nent and universal amplitude ratios. This analysis is based on variati onal approximations of the eigenstates of the Markov matrix describing heat-bath, single-spin-Aip dynamics. Monte Carlo computation of the c orresponding autocorrelations and cross correlations, in which the var iational error is systematically reduced, yields eigenvalues and the a ssociated relaxation times with considerably higher statistical accura cy than is the case for traditional correlations.