Scaling and multiscaling in the ordering kinetics of a conserved order parameter

The ordering kinetics of a conserved order parameter with O(n) symmetry are studied using the approach of Mazenko. Conventional scaling is obtained for any finite n, while for n strictly infinite the multiscaling form found by Coniglio and Zannetti is recovered. The two different results can be understood in terms of the different orders in which the limits n→∞ and t→∞ are taken. For large, finite n the characteristic scale grows as L(t)∼(t/ln n${)}^{1/4}$ for t→∞.