title: Precise toppling balance, quenched disorder, and universality for sandpiles.
abstract: A single sandpile model with quenched random toppling matrices captures the crucial features of different models of self-organized criticality. With symmetric matrices avalanche statistics falls in the multiscaling Bak-Tang-Wiesenfeld universality class. In the asymmetric case the simple scaling of the Manna model is observed. The presence or absence of a precise toppling balance between the amount of sand released by a toppling site and the total quantity the same site receives when all its neighbors topple once determines the appropriate universality class.
authors.affiliation: Satyendra Nath Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata-700098, India.
authors.forename: R
authors.initials: R
authors.lastname: Karmakar
authors.forename: S S
authors.initials: SS
authors.lastname: Manna
authors.forename: A L
authors.initials: AL
authors.lastname: Stella