Aging dynamics and density relaxation in kinetic lattice gases under gravity

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