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arXiv 0905.3260cond-mat.dis-nn
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图上伊辛自旋平行动力学的空腔方法

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

I. Neri, D. Bollé

AI总结:

本文用空腔方法研究图上无序伊辛模型的平行动力学,推导出沿边传播路径的递归方程,在树上精确,并给出有向图的平稳分布及相图,理论预测获模拟验证。

摘要:

我们使用空腔方法研究图上无序伊辛模型的平行动力学。具体而言,我们推导出一组递归方程,这些方程涉及沿图的边传播的路径的单点概率。这些方程类似于平衡模型的空腔方程,并且在树上是精确的。在边完全有向的图上,我们找到了自旋平稳分布的精确表达式。我们给出了非对称贝特晶格上的伊辛模型以及非对称无标度图上具有赫布相互作用的神经网络的相图。对于具有非零比例对称边的图,这些方程可以在有限时间步数内求解。理论预测得到了模拟结果的证实。使用一种启发式方法,我们将空腔方程扩展为一组方程,这些方程确定了具有非零比例对称边的图上伊辛模型平稳分布的边缘分布。我们讨论了该方法的结果,并与模拟进行了比较。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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