A one-dimensional stochastic sandpile with constant profile width

A sandpile model with dynamically varying critical heights is studied in on e dimension. The model display self-organized critical behavior with an ava lanche exponent tau = 1.35 +/- 0.02, which correspond to the value found fr om a mean-field argument. The time evolution of the mass and height of the pile is characterized by a time-correlation function with a crossover time that increases systematically with system time. The average transit time of a grain through the model is proportional to the system size, but the dist ribution of transit times has a power-law tail. A modified model, which inc ludes non-local interactions from force propagation with in the pile, belon gs to the same universality class, although the distribution of transit tim es changes significantly. (C) 1999 Elsevier Science B.V. All rights reserve d.