Dynamical real space renormalization group applied to sandpile models

A general framework for the renormalization group analysis of self-organize d critical sandpile models is formulated. The usual real space renormalizat ion scheme for lattice models when applied to nonequilibrium dynamical mode ls must be supplemented by feedback relations coming from the stationarity conditions. On the basis of these ideas the dynamically driven renormalizat ion group is applied to describe the boundary and bulk critical behavior of sandpile models. A detailed description of the branching nature of sandpil e avalanches is given in terms of the generating functions of the underlyin g branching process. [S1063-651X(99)06006-7].