HR: 0800h
AN: SM51B-0536    [Abstracts]
TI: A stochastic theory for temporal fluctuations in Self-Organized Critical systems.
AU: * Rypdal, M
EM: Martin.Rypdal@matnat.uit.no
AF: Department of mathematics and statistics, University of Tromso, Tromso, 9037, Norway
AU: Rypdal, K
EM: kris@phys.uit.no
AF: Department of Physics, University of Tromso, Tromso, 9037, Norway
AB: In this work we use a mean field assumption to derive simple stochastic differential equation for the toppling activity in the Bak-Tang-Wiesenfeld (BTW) sandpile models, modelling the activity as an anti persistent fractional Brownian "super-walk", where the diffusion coefficient is proportional to the activity level itself. Through analysis of the stochastic differential equation and analytical solutions of the corresponding Fokker- Planck equation it is possible predict all the essential statistical properties of the toppling signal, including its spectral properties and the probability density functions for duration-times and the fluctuations in the signal itself. The methods used are insensitive to the particular details of the BTW class models, and can easily be modified to include other sandpile models.
DE: 4480 Self-organized criticality
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting