AVALANCHES, TRANSPORT, AND LOCAL EQUILIBRIUM IN SELF-ORGANIZED CRITICALITY

We obtain numerical evidence of local equilibrium in a family of sandp ile models which exhibit self-organized criticality (SOC), by comparin g them with closed systems which exhibit dynamical depinning transitio ns. In particular, we construct a mapping between the open and closed system avalanche size distributions which accounts for finite size flu ctuations in the density and the critical point. Our results suggest a generalization of the singular diffusion description of SOC which tra nscends the point where this description was previously seen to break down. [S1063-651X(98)15811-7].