Dynamics of condensation in zero-range processes

The dynamics of a class of zero-range processes exhibiting a condensation transition in the stationary state is studied. The system evolves in time starting from a random disordered initial condition. The analytical study of the large-time behaviour of the system in its mean-field geometry provides a guide for the numerical study of the one-dimensional version of the model. Most qualitative features of the mean-field case are still present in the one-dimensional system, both in the condensed phase and at criticality. In particular the scaling analysis, valid for the mean-field system at large time and for large values of the site occupancy, still holds in one dimension. The dynamical exponent z, characteristic of the growth of the condensate, is changed from its mean-field value 2 to 3. In the presence of a bias, the mean-field value z = 2 is recovered. The dynamical exponent z(c) characteristic of the growth of critical fluctuations, is changed from its mean-field value 2 to a larger value, z(c) similar or equal to 5. In the presence of a bias, z(c) similar or equal to 3.