Virginia TechLeung, K. T.2014-05-072014-05-071991-09Leung, K. T., "Power spectrum of the current in systems with a conserved density," Phys. Rev. B 44, 5340(R) DOI: http://dx.doi.org/10.1103/PhysRevB.44.53400163-1829http://hdl.handle.net/10919/47874Motivated by recent studies of model sandpiles, the power spectrum S of the current in dissipative dynamical systems with a conserved density is investigated. In contrast to self-organized criticality exhibited in certain lattice gases and noisy Langevin equations, where power laws are described by universal, simple indices, the index of S(f) for small frequency f is determined at a second-order phase transition by nontrivial critical exponents. For systems with no external drive (i.e., model B), the exact result for the dynamic exponent z is rederived. With drive (driven diffusive systems), the index is given by the exponent of anisotropies. Simulation in two dimensions yields good agreements with theoretical predictions.en-USIn Copyrightdriven diffusive systemsself-organized criticalitystochastic latticesystemsphase-transitions1/f noisefield-theorycritical-behaviorgas modelsequilibriumdynamicsphysics, condensed matterArticle - Refereedhttp://journals.aps.org/prb/abstract/10.1103/PhysRevB.44.5340https://doi.org/10.1103/PhysRevB.44.5340