Departamento de Física, Universidade Federal do Ceará, Campus do Pici, 60455-760 Fortaleza, Brazil.
Computational Physics, IfB, ETH Zurich, Stefano-Franscini-Platz 3, CH-8093 Zurich, Switzerland.
Phys Rev E. 2016 Apr;93:042124. doi: 10.1103/PhysRevE.93.042124. Epub 2016 Apr 21.
We disclose the origin of anisotropic percolation perimeters in terms of the stochastic Loewner evolution (SLE) process. Precisely, our results from extensive numerical simulations indicate that the perimeters of multilayered and directed percolation clusters at criticality are the scaling limits of the Loewner evolution of an anomalous Brownian motion, being superdiffusive and subdiffusive, respectively. The connection between anomalous diffusion and fractal anisotropy is further tested by using long-range power-law correlated time series (fractional Brownian motion) as the driving functions in the evolution process. The fact that the resulting traces are distinctively anisotropic corroborates our hypothesis. Under the conceptual framework of SLE, our study therefore reveals different perspectives for mathematical and physical interpretations of non-Markovian processes in terms of anisotropic paths at criticality and vice versa.
我们根据随机 Loewner 演化(SLE)过程揭示了各向异性渗滤边界的起源。具体来说,我们通过广泛的数值模拟结果表明,在临界点处的多层和有向渗流簇的边界分别是异常布朗运动的 Loewner 演化的标度极限,它们分别是超扩散和亚扩散的。我们还通过使用长程幂律相关时间序列(分数布朗运动)作为演化过程中的驱动函数,进一步检验了反常扩散和分形各向异性之间的联系。事实证明,所得轨迹具有明显的各向异性,这证实了我们的假设。因此,在 SLE 的概念框架下,我们的研究揭示了在临界点处各向异性路径方面对非马尔可夫过程的数学和物理解释的不同视角,反之亦然。