Exact phase diagram of a model with aggregation and chipping - art. no. 036114

We reexamine a simple lattice model of aggregation in which masses diffuse and coalesce upon contact with rate 1 and every nonzero mass chips off a si ngle unit of mass and adds it to a randomly chosen neighbor with rate w. Th e dynamics conserves the average mass density rho and in the stationary sta te the system undergoes a nonequilibrium phase transition in the (rho -w) p lane across a critical line rho (c)(w). In this paper, we show analytically that in arbitrary spatial dimensions rho (c)(w)= rootw+1-1 exactly and hen ce, remarkably, is independent of dimension. We also provide direct and ind irect numerical evidence that strongly suggests that the mean field asympto tic results for the single site mass distribution function and the associat ed critical exponents are superuniversal, i.e., independent of dimension.