SINGLE CLUSTER DYNAMICS FOR THE INFINITE-RANGE O(N) MODEL

This paper presents a study of Wolff's single cluster acceleration alg orithm for O(n) models in the infinite range or mean-field limit. Nume rical results for n = 2, 3 and 4 are consistent with the complete elim ination of critical slowing down. Also a heuristic argument is advance d to support the value of z = 0 for the dynamic critical exponent. A n ew cluster growth algorithm is formulated for the infinite range model that has optimal efficiency of O(N) in the system size N for the Swen dsen-Wang update scheme. Using an asymptotically correct version of th is cluster method, we are able to perform simulations for the Wolff up date scheme up to 262,144 spins for 10(5) time steps for the O(N) mode ls.