The lattice gas model in equilibrium is considered. We give a lower bound of the density-density time correlation for large time, which involves the bulk diffusion matrix in a physically natural way.
"A Lower Bound for Time Correlation of Lattice Gases." Electron. Commun. Probab. 4 1 - 8, 1999. https://doi.org/10.1214/ECP.v4-999