Usefulness of an equal-probability assumption for out-of-equilibrium states: a master equation approach
Usefulness of an equal-probability assumption for out-of-equilibrium states: a master equation approach
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等概率假设对于非平衡状态的有用性：主方程方法
DOI：
10.1103/physreve.86.041133
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
and Hiroshi Watanabe
中科院分区：
文献类型：
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作者：
Tomoaki Nogawa;Nobuyasu Ito;and Hiroshi Watanabe
我们考察了假设远离平衡态的概率相等的有效性。为此，我们提出了一种构造描述非平稳非平衡动力学的广泛变量的主方程的方法。该方法的关键点是假定瞬态态等价于具有相同外延变量的平衡态，即处于非平衡状态的微观态具有相同的概率。我们通过蒙特卡罗模拟演示了该方法在二维Potts模型临界弛豫中的应用。对于平衡而言，单变量描述产生了非常快的松弛动力学，而冗余的双变量描述则很好地定量地再现了真实动力学。这些结果表明，某些类型的非平衡态可以用小范围的自由度来描述，这可能会导致另一种理解非平衡现象的方法。
We examine the effectiveness of assuming an equal probability for states far from equilibrium. For this aim, we propose a method to construct a master equation for extensive variables describing nonstationary nonequilibrium dynamics. The key point of the method is the assumption that transient states are equivalent to the equilibrium state that has the same extensive variables, i.e., an equal probability holds for microscopic states in nonequilibrium. We demonstrate an application of this method to the critical relaxation of the two-dimensional Potts model by Monte Carlo simulations. While the one-variable description, which is adequate for equilibrium, yields relaxation dynamics that are very fast, the redundant two-variable description well reproduces the true dynamics quantitatively. These results suggest that some class of the nonequilibrium state can be described with a small extension of degrees of freedom, which may lead to an alternative way to understand nonequilibrium phenomena.