GENERALIZED SANDPILE MODEL AND THE CHARACTERIZATION OF THE EXISTENCE OF SELF-ORGANIZED CRITICALITY

We consider a generalized sandpile model where the particle addition and toppling are formulated in terms of mappings. In this way, the toppling rules and toppling conditions of the system can also be completely general. Even under these extremely relaxed conditions, we can still find an if and only if condition for the existence of an absolute steady state. Moreover, such a kind of absolute steady state often exhibits self-organized criticality. Our model is a superset of both the original Bak-Tang-Wiesenfeld sandpile and the Abelian sandpile models. Finally, we shall demonstrate the importance of both the particle-addition methods and the boundary conditions to the self-organized critical phenomena of a physical system.