Velocity correlations in a one-dimensional lattice gas: theory and simulations

In a one-dimensional fluid the macroscopic Navier-Stokes equations are no longer valid because of long-time tails and diverging transport coefficients. By performing computer simulations on a one-dimensional cellular automaton fluid we have investigated the ranges of times and densities where the intermediate- and long-time behavior of the velocity correlation function is correctly described by mode-coupling theory. The agreement is in general surprisingly good.