Brito, RicardoErnst, M. H.2023-06-202023-06-201992-07-151050-294710.1103/PhysRevA.46.875https://hdl.handle.net/20.500.14352/58614©1992 The American Physical Society. It is a pleasure to thank J.W. Dufty, D. Frenkel, M. van der Hoef, and G.A. van Velzen for many stimulating and clarifying discussions. R.B. acknowledges support from a DGICYT Project No. PB88-0140 and M.H.E from a NATO Collaborative Research Grant.The kinetic theory for tagged-particle problems in lattice-gas cellular automata is extended beyond Boltzmann's mean-field approximation by including correlated ring-type collisions. This theory provides explicit expressions for the velocity autocorrelation function (VACF) for all times in terms of the ring-collision integral, as well as corrections to the Boltzmann values of the transport coefficients. For times long compared to the mean free time, the ring integral equation yields the phenomenological mode-coupling theory and the long-time tails. For intermediate times it describes a slow transition from initial exponential decay to the long-time tails. At short times the ring kinetic theory is exact. In particular, deviations from the Boltzmann result in the VACF of three-dimensional systems after two time steps are calculated explicitly and compared with computer simulations.engjournal articlehttp://pra.aps.org/pdf/PRA/v46/i2/p875_1http://pra.aps.org/open access536Velocity Autocorrelation FunctionCellular-Automata FluidsMode-Coupling TheoryLong-Time TailsFaster-Than-T-1 DecayDiffusionTermodinámica2213 Termodinámica