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arXiv 2108.09260cond-mat.stat-mech
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平面网络上输运的首次通过时间及其与离网平面扩散的关系

First passage times of transport on planar spatial networks and their connections to off-network planar diffusion

D. B. Wilson, C. H. L. Beentjes

摘要:

考虑嵌入2D平面中的网络,其中粒子沿着网络的边扩散。很明显,在短的长度尺度上,粒子沿着单个边缘移动,因此经历一维扩散。然而,在更大的长度尺度上,它不再是立即清楚的运输将如何表现。人们可以凭直觉认为,当网络嵌入到“足够大”的长度尺度的二维中时,传输也将呈现二维。所有网络都是如此吗?我们能量化这种转变发生的长度尺度吗?中间空间尺度上的迁移行为是什么?在本文中,我们回答了这些问题,提出了一个数值线性代数方法,提供了一个给定的网络的第一次通过时间的确切时刻。将这些网络化的首次通过时间与平面扩散的首次通过时间进行比较,揭示了网络化传输的几个有趣特性。特别是,我们可以直接量化网络扩散将出现平面的长度尺度,如果它确实如此的话。最后,我们引入了一个适应的方法,最大熵使用的时刻的首次通过时间构建一个解析近似的首次通过时间的整个概率分布。

英文摘要:

Consider a network embedded in the 2D plane, where a particle diffuses along the edges of the network. It is clear that over short length scales a particle moves along a single edge and thus undergoes one-dimensional diffusion. However, on larger length scales it is no longer immediately clear how the transport will behave. One could intuit that as the network is embedded in two dimensions for "large enough" length scales the transport will also appear two-dimensional. Is this true for all networks? Can we quantify the length scales upon which this transition occurs? What is the transport behaviour on intermediate spatial scales? In this paper, we answer these question by presenting a numerical linear algebra approach that provides the exact moments of first passage times for a given network. Comparing these networked first-passage times to first-passage times for planar diffusion reveals several interesting properties of networked transport. In particular we can directly quantify the length scale upon which networked diffusion will appear planar if it does at all. Finally, we introduce an adaptation of the method of maximum entropy to use the moments of first-passage times to construct an analytical approximation to the first-passage times entire probability distribution.

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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