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 the 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.Comment: 12 pages, 8 figures. Matching the version published in Phys. Rev.
