Nonlinearities in conservative growth equations

Abstract

Using the dynamic renormalization group technique, we analyze general nonlinearities in a conservative nonlinear growth equation with nonconserved Gaussian white noise. We show that they fall into two classes only: the Edwards-Wilkinson and Lai-Das Sarma types, by explicitly computing the associated amputated two and three point functions at the first order in perturbation parameter(s). We further generalize this analysis to higher order nonlinearities and also suggest a physically meaningful geometric interpretation of the same.