Effective potential for the massless KPZ equation

In previous work we have developed a general method for casting a classical field theory subject to Gaussian noise (that is, a stochastic partial diff erential equation (SPDE)) into a functional integral formalism that exhibit s many of the properties more commonly associated with quantum field theori es (QFTs). In particular, we demonstrated how to derive the one-loop effect ive potential. In this paper we apply the formalism to a specific field the ory of considerable interest, the massless KPZ equation (massless noisy Bur gers equation), and analyze its behavior in the ultraviolet (short-distance ) regime. When this field theory is subject to white noise we can calculate the one-loop effective potential and show that it is one-loop ultraviolet renormalizable in 1, 2, and 3 space dimensions, and fails to be ultraviolet renormalizable in higher dimensions. We show that the one-loop effective p otential for the massless KPZ equation is closely related to that for lambd a phi(4) QFT. In particular, we prove that the massless KPZ equation exhibi ts one-loop dynamical symmetry breaking (via an analog of the Coleman-Weinb erg mechanism) in 1 and 2 space dimensions, and that this behavior does not persist in 3 space dimensions. (C) 2000 Elsevier Science B.V. All rights r eserved.