UNIVERSAL AMPLITUDES OF POWER-LAW TAILS IN THE ASYMPTOTIC STRUCTURE FACTOR OF SYSTEMS WITH TOPOLOGICAL DEFECTS

We compute the asymptotic structure factor S (k, t) of the O(n) model for n less-than-or-equal-to d, where d and n are the dimensions of space and of the order parameter, respectively. Topological defects in the field lead to the power-law tail S (k, t) = A (n, d)rho(t)k-(d+n), where rho is the defect density. The amplitude A (n,d) is calculated exactly using purely geometrical arguments based on the defect field.