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arXiv 2103.09032cond-mat.stat-mechmath-phmath.MPphysics.data-an
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分数阶布朗运动的泛函与反正弦三定律

Functionals of fractional Brownian motion and the three arcsine laws

Tridib Sadhu, Kay Jörg Wiese

摘要:

分数布朗运动是一个非马尔可夫高斯过程的赫斯特指数$H\in [0,1]$,推广标准的布朗运动占异常扩散。这个过程的泛函作为非平衡动力学的标准参考点,在实际应用中非常重要。我们描述了一个扰动扩展,使我们能够评估许多非平凡的观测分析:我们概括了著名的三个反正弦定律的标准布朗运动。泛函是:(i)该过程保持正的时间的分数,(ii)该过程最后访问原点的时间,以及(iii)该过程达到其最大值(或最小值)的时间。我们推导出这三个泛函的概率表达式作为$ε= H-\tfrac{1}{2}$的扩展,高达二阶。我们发现,这三个概率是不同的,除了$H=\tfrac{1}{2}$,他们重合。数值模拟结果证实了我们的结果具有较高的精度。

英文摘要:

Fractional Brownian motion is a non-Markovian Gaussian process indexed by the Hurst exponent $H\in [0,1]$, generalising standard Brownian motion to account for anomalous diffusion. Functionals of this process are important for practical applications as a standard reference point for non-equilibrium dynamics. We describe a perturbation expansion allowing us to evaluate many non-trivial observables analytically: We generalize the celebrated three arcsine-laws of standard Brownian motion. The functionals are: (i) the fraction of time the process remains positive, (ii) the time when the process last visits the origin, and (iii) the time when it achieves its maximum (or minimum). We derive expressions for the probability of these three functionals as an expansion in $ε= H-\tfrac{1}{2}$, up to second order. We find that the three probabilities are different, except for $H=\tfrac{1}{2}$ where they coincide. Our results are confirmed to high precision by numerical 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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