Nezhadhaghighi Mohsen Ghasemi, Nakhlband Abbas
Department of Physics, Shiraz University, Shiraz 71454, Iran.
Department of Physics, Sharif University of Technology, Tehran 14588-89694, Iran.
Phys Rev E. 2017 Apr;95(4-1):042114. doi: 10.1103/PhysRevE.95.042114. Epub 2017 Apr 7.
In this paper, we investigate and develop an alternative approach to the numerical analysis and characterization of random fluctuations with the heavy-tailed probability distribution function (PDF), such as turbulent heat flow and solar flare fluctuations. We identify the heavy-tailed random fluctuations based on the scaling properties of the tail exponent of the PDF, power-law growth of qth order correlation function, and the self-similar properties of the contour lines in two-dimensional random fields. Moreover, this work leads to a substitution for the fractional Edwards-Wilkinson (EW) equation that works in the presence of μ-stable Lévy noise. Our proposed model explains the configuration dynamics of the systems with heavy-tailed correlated random fluctuations. We also present an alternative solution to the fractional EW equation in the presence of μ-stable Lévy noise in the steady state, which is implemented numerically, using the μ-stable fractional Lévy motion. Based on the analysis of the self-similar properties of contour loops, we numerically show that the scaling properties of contour loop ensembles can qualitatively and quantitatively distinguish non-Gaussian random fields from Gaussian random fluctuations.
在本文中,我们研究并开发了一种替代方法,用于对具有重尾概率分布函数(PDF)的随机波动进行数值分析和表征,例如湍流热流和太阳耀斑波动。我们基于PDF尾指数的标度性质、q阶相关函数的幂律增长以及二维随机场中轮廓线的自相似性质来识别重尾随机波动。此外,这项工作引出了一个在存在μ稳定列维噪声时有效的分数阶爱德华兹 - 威尔金森(EW)方程的替代方程。我们提出的模型解释了具有重尾相关随机波动的系统的构型动力学。我们还给出了在稳态下存在μ稳定列维噪声时分数阶EW方程的另一种解法,该解法通过使用μ稳定分数阶列维运动进行数值实现。基于对轮廓环自相似性质的分析,我们通过数值表明轮廓环系综的标度性质可以定性和定量地区分非高斯随机场与高斯随机波动。