Asymptotic structure factor and power-law tails for phase ordering in systems with continuous symmetry

We compute the asymptotic structure factor S₊ (t) =L (t) ^dg (kL (t) ), where L (t) is a time-dependent characteristic length scale and d is the dimensionality for a system with a nonconserved n-component vector order parameter quenched into the ordered phase. The well-known Ohta-Jasnow-Kawasaki-Yalabik-Gunton result is recovered for n=1. The scaling function g (x) has the large-x behavior g (x) x^- (d+n), which includes Porod's law (for n=1) as a special case.