Aging dynamics and density relaxation in granular compaction
  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 find that logarithmic compaction and simple aging are intimately related to the Vogel-Fulcher law, while power-law compaction and super-aging behavior occur in presence of a power-law diffusion. 
Y. Levin, J.J. Arenzon, M. Sellitto