High-precision monte carlo study of the 3D XY-universality class

We present a Monte Carlo study of the two-component phi(4) model on the sim ple cubic lattice in three dimensions. By suitable tuning of the coupling c onstant, lambda, we eliminate leading order corrections to sealing. High-st atistics simulations using finite-size scaling techniques yield nu = 0.6723 (3) [8] and eta = 0.0381(2)[2], where the statistical and systematical erro rs are given in the first and second bracket, respectively. These results a re more precise than any previous theoretical estimate of the critical expo nents for the 3D XP universality class.