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Crossover in the Slow Decay of Dynamic Correlations in the Lorentz Model

Felix Höfling·Thomas Franosch
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Abstract

The long-time behavior of transport coefficients in a model for spatially heterogeneous media in two and three dimensions is investigated by Molecular Dynamics simulations. The behavior of the velocity auto-correlation function is rationalized in terms of a competition of the critical relaxation due to the underlying percolation transition and the hydrodynamic power-law anomalies. In two dimensions and in the absence of a diffusive mode, another power law anomaly due to trapping is found with an exponent -3 instead of -2. Further, the logarithmic divergence of the Burnett coefficient is corroborated in the dilute limit; at finite density, however, it is dominated by stronger divergences.

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Felix Höfling, Thomas Franosch. 2007-02-27. Crossover in the Slow Decay of Dynamic Correlations in the Lorentz Model. https://doi.org/10.1103/physrevlett.98.140601

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