Conservation Laws and Discrete Harmonicity in the Fixed Energy Sandpile
Mario Casartelli
Abstract
The deterministic Bak-Tang-Wiesenfeld automaton on the two dimensional torus, or Fixed Energy Sandpile, is studied in order to characterize the structure of basins of attraction and the mean behavior of transients and periodical orbits vs. the torus size. The link between discrete harmonicity and invariant quantities is shown, and an almost complete classification of effective independent constants of motion is found. The robustness of this structure is checked by introducing several deterministic perturbations. In some cases, such perturbed systems may be seen as a step in the definition of a wide class of deterministic intermittent models.
Elenco dei partecipanti al convegno di Bari.