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arXiv 0711.4261math-phcond-mat.dis-nncond-mat.stat-mechmath.MP
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单阶和分布阶分数阶扩散方程的若干问题

Some aspects of fractional diffusion equations of single and distributed order

Francesco Mainardi, Gianni Pagnini, Rudolf Gorenflo

摘要:

通过用$β\in (0,1)$阶的分数阶导数替换一阶时间导数,从标准扩散方程获得时间分数阶扩散方程。柯西问题的基本解被解释为一个自相似的非马尔可夫随机过程的概率密度与亚扩散现象(方差随时间次线性增长)。通过考虑阶数小于1的分数阶时间导数的连续或离散分布,得到了进一步的推广。那么基本解仍然是一个非马尔可夫过程的概率密度,然而,它不再是自相似的,而是表现出相应的时间尺度分布。

英文摘要:

The time fractional diffusion equation is obtained from the standard diffusion equation by replacing the first-order time derivative with a fractional derivative of order $β\in (0,1)$. The fundamental solution for the Cauchy problem is interpreted as a probability density of a self-similar non-Markovian stochastic process related to a phenomenon of sub-diffusion (the variance grows in time sub-linearly). A further generalization is obtained by considering a continuous or discrete distribution of fractional time derivatives of order less than one. Then the fundamental solution is still a probability density of a non-Markovian process that, however, is no longer self-similar but exhibits a corresponding distribution of time-scales.

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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