SCALING OF FLUCTUATIONS IN ONE-DIMENSIONAL INTERFACE AND HOPPING MODELS

We study time-dependent correlation functions in a family of one-dimensional biased stochastic lattice-gas models in which particles can move up to k lattice spacings. In terms of equivalent interface models, the family interpolates between the low-noise Ising (k = 1) and Toom (k = infinity) interfaces on a square lattice. Since the continuum description of density (or height) fluctuations in these models involves at most (k + 1)th-order terms in a gradient expansion, we can test specific renormalization-group predictions using Monte Carlo methods to probe scaling behavior. In particular we confirm the existence of multiplicative logarithms in the temporal behavior of mean-squared height fluctuations [approximately t1/2(ln t)1/4], induced by a marginal cubic gradient term. Analogs of redundant operators, familiar in the context of equilibrium systems, also appear to occur in these nonequilibrium systems.