The Cavity Approach to Parallel Dynamics of Ising Spins on a Graph

Fuente: arXiv
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Main Authors: Neri, I., Bollé, D.
Format: Preprint
Published: 2009
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author Neri, I.
Bollé, D.
author_facet Neri, I.
Bollé, D.
contents We use the cavity method to study parallel dynamics of disordered Ising models on a graph. In particular, we derive a set of recursive equations in single site probabilities of paths propagating along the edges of the graph. These equations are analogous to the cavity equations for equilibrium models and are exact on a tree. On graphs with exclusively directed edges we find an exact expression for the stationary distribution of the spins. We present the phase diagrams for an Ising model on an asymmetric Bethe lattice and for a neural network with Hebbian interactions on an asymmetric scale-free graph. For graphs with a nonzero fraction of symmetric edges the equations can be solved for a finite number of time steps. Theoretical predictions are confirmed by simulation results. Using a heuristic method, the cavity equations are extended to a set of equations that determine the marginals of the stationary distribution of Ising models on graphs with a nonzero fraction of symmetric edges. The results of this method are discussed and compared with simulations.
format Preprint
id arxiv_https___arxiv_org_abs_0905_3260
institution arXiv
publishDate 2009
record_format arxiv
spellingShingle The Cavity Approach to Parallel Dynamics of Ising Spins on a Graph
Neri, I.
Bollé, D.
Disordered Systems and Neural Networks
We use the cavity method to study parallel dynamics of disordered Ising models on a graph. In particular, we derive a set of recursive equations in single site probabilities of paths propagating along the edges of the graph. These equations are analogous to the cavity equations for equilibrium models and are exact on a tree. On graphs with exclusively directed edges we find an exact expression for the stationary distribution of the spins. We present the phase diagrams for an Ising model on an asymmetric Bethe lattice and for a neural network with Hebbian interactions on an asymmetric scale-free graph. For graphs with a nonzero fraction of symmetric edges the equations can be solved for a finite number of time steps. Theoretical predictions are confirmed by simulation results. Using a heuristic method, the cavity equations are extended to a set of equations that determine the marginals of the stationary distribution of Ising models on graphs with a nonzero fraction of symmetric edges. The results of this method are discussed and compared with simulations.
title The Cavity Approach to Parallel Dynamics of Ising Spins on a Graph
topic Disordered Systems and Neural Networks
url https://arxiv.org/abs/0905.3260