SCALING AND CROSSOVER IN THE LARGE-N MODEL FOR GROWTH-KINETICS

The dependence of the scaling properties of the structure factor on space dimensionality, range of interaction, initial and final conditions, and the presence or absence of a conservation law is analyzed in the framework of the large-N model for growth kinetics. The variety of asymptotic behaviors is quite rich, including standard scaling, multiscaling, and a mixture of the two. The different scaling properties obtained as the parameters are varied are controlled by a structure of fixed points with their domains of attraction. Crossovers arising from the competition between distinct fixed points are explicitly obtained. Temperature fluctuations below the critical temperature are not found to be irrelevant when the order parameter is conserved. The model is solved by integration of the equation of motion for the structure factor and by a renormalization group approach.