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arXiv 1104.2064cond-mat.stat-mech
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广义熵何时适用?相空间体积如何决定熵

When do generalized entropies apply? How phase space volume determines entropy

Rudolf Hanel, Stefan Thurner

摘要:

我们展示了经典系统的相空间体积$Ω(N)$对它的大小$N$的依赖性如何唯一地决定它的广延熵。我们给出了一个简洁的标准时,这个熵是不是玻尔兹曼吉布斯型,但必须采取{ \em广义}(非加性)的形式。我们表明,广义熵只能存在时,系统中的自由度的动态(统计)相关分数在热力学极限消失。在这些系统中,大部分自由度被冻结,并且实际上在统计上是不活跃的。因此,由广义熵控制的系统是相空间体积有效地坍缩到低维“表面”的系统。我们明确地说明了二项式过程的情况,并认为广义熵可能是相关的自组织临界系统,如沙堆,自旋系统,形成元结构,如旋涡,域,瞬子等,以及与异常扩散相关的问题。

英文摘要:

We show how the dependence of phase space volume $Ω(N)$ of a classical system on its size $N$ uniquely determines its extensive entropy. We give a concise criterion when this entropy is not of Boltzmann-Gibbs type but has to assume a {\em generalized} (non-additive) form. We show that generalized entropies can only exist when the dynamically (statistically) relevant fraction of degrees of freedom in the system vanishes in the thermodynamic limit. These are systems where the bulk of the degrees of freedom is frozen and is practically statistically inactive. Systems governed by generalized entropies are therefore systems whose phase space volume effectively collapses to a lower-dimensional 'surface'. We explicitly illustrate the situation for binomial processes and argue that generalized entropies could be relevant for self organized critical systems such as sand piles, for spin systems which form meta-structures such as vortices, domains, instantons, etc., and for problems associated with anomalous diffusion.

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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