AVALANCHE DYNAMICS FROM ANOMALOUS DIFFUSION

Bak, Tang, and Wiesenfeld introduced a sandpile model to study the so- called self-organized critical phenomena [P. Bak, C. Tang, and K. Wies enfeld, Phys. Rev. A 38, 364 (1988)]. There were several proposals to connect this discrete cellular automaton model with diffusion processe s. We show how one may interpret the dynamics of this model as a discr etized version of an anomalous diffusion equation, and we study the ti me evolution of the model off criticality.