Aging dynamics and density relaxation in kinetic lattice gases under gravity

We present an analytical approach to the out-of-equilibrium dynamics of a class of kinetic lattice gases under gravity. The location of the jamming transition, the critical exponents, and the scaling functions characterizing the relaxation processes are determined. In particular, we nd that logarithmic compaction and simple aging are intimately related to the Vogel-Fulcher law, while power law compaction and super-aging behavior occur in the presence of a power law diffusion.