Dynamic critical exponent of the three-dimensional classical XY model

Our previous result for the value of the dynamic critical exponent z in the three-dimensional classical XY model differs from that obtained by Krech and Landau. Their results are consistent with the weak scaling fixed point solution of De Dominicis and Peliti, while ours correspond to the dynamic scaling fixed point solution of Hohenberg and Halperin. In order to see whether the difference is due to our small lattice size, we increased the lattice size L x L x L up to L = 30. We tried differing definitions for the characteristic time, based on the variation of the correlation function in height and in area covered. We consistently obtained almost identical values for z. Our new estimate for z is 1.500(g), where the number inside the parentheses denotes the 95 % confidence interval of the curve fit. This again supports the Hohenberg-Halperin behavior of the model.