Anomalous dynamical scaling in anharmonic chains and plasma models with multiparticle collisions

Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Dec;92(6):062108. doi: 10.1103/PhysRevE.92.062108. Epub 2015 Dec 4.

Abstract

We study the anomalous dynamical scaling of equilibrium correlations in one-dimensional systems. Two different models are compared: the Fermi-Pasta-Ulam chain with cubic and quartic nonlinearity and a gas of point particles interacting stochastically through multiparticle collision dynamics. For both models-that admit three conservation laws-by means of detailed numerical simulations we verify the predictions of nonlinear fluctuating hydrodynamics for the structure factors of density and energy fluctuations at equilibrium. Despite this, violations of the expected scaling in the currents correlation are found in some regimes, hindering the observation of the asymptotic scaling predicted by the theory. In the case of the gas model this crossover is clearly demonstrated upon changing the coupling constant.

Publication types

  • Research Support, Non-U.S. Gov't