PHASE-ORDERING DYNAMICS OF THE O(N) MODEL - EXACT PREDICTIONS AND NUMERICAL RESULTS

We consider the pair correlation functions of both the order parameter field and its square for phase ordering in the O(n) model with a nonconserved order parameter in spatial dimension 2 less-than-or-equal-to d less-than-or-equal-to 3 and spin dimension 1 less-than-or-equal-to n less-than-or-equal-to d. We calculate, in the scaling limit, the exact short-distance singularities of these correlation functions and compare these predictions to numerical simulations. Our results suggest that the scaling hypothesis does not hold for the d = 2 O(2) model.