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In a fractional Cauchy problem, the usual first order time derivative is replaced by a fractional derivative. This problem was first considered by \citet{nigmatullin}, and \citet{zaslavsky} in $\mathbb R^d$ for modeling some physical…

Probability · Mathematics 2016-11-29 Erkan Nane

Based on the non-Markov diffusion equation taking into account the spatial fractality and modeling for the generalized coefficient of particle diffusion…

Statistical Mechanics · Physics 2024-06-19 P. Kostrobij , M. Tokarchuk , B. Markovych , I. Ryzha

The diffusion equation and its time-fractional counterpart can be obtained via the diffusion limit of continuous-time random walks with exponential and heavy-tailed waiting time distributions. The space dependent variable-order…

Statistical Mechanics · Physics 2025-10-24 Christopher N. Angstmann , Daniel S. Han , Bruce I. Henry , Boris Z. Huang , Zhuang Xu

We start with a general governing equation for diffusion transport, written in a conserved form, in which the phenomenological flux laws can be constructed in a number of alternative ways. We pay particular attention to flux laws that can…

Analysis of PDEs · Mathematics 2019-02-22 Tokinaga Namba , Piotr Rybka , Vaughan Voller

We study the dynamics of a Brownian particle in a strongly correlated quenched random potential defined as a periodically-extended (with period $L$) finite trajectory of a fractional Brownian motion with arbitrary Hurst exponent $H \in…

Statistical Mechanics · Physics 2014-09-01 David S. Dean , Shamik Gupta , Gleb Oshanin , Alberto Rosso , Gregory Schehr

Fractional Dzherbashian-Nersesian operator is considered and three famous fractional order derivatives namely Riemann-Liouville, Caputo and Hilfer derivatives are shown to be special cases of the earlier one. The expression for Laplace…

Analysis of PDEs · Mathematics 2021-11-09 Anwar Ahmad , Muhammad Ali , Salman A. Malik

We prove that probability laws of certain multidimensional semimartingales which includes time-inhomogenous diffusions, under suitable assumptions, satisfy Quadratic Transportation Cost Inequality under the uniform metric. From this we…

Probability · Mathematics 2011-04-22 Soumik Pal

Power laws in time and frequency appear in fields such as linear viscoelasticity and acoustics, viscous boundary layer problems, and dielectrics. This is consistent with fractional derivatives in the fundamental descriptions, since power…

General Physics · Physics 2023-08-16 Sverre Holm

The fractional Brownian motion can be considered as a Gaussian field indexed by $(t,H)\in {\mathbb{R}_{+}\times (0,1)}$, where $H$ is the Hurst parameter. On compact time intervals, it is known to be almost surely jointly H\"older…

Probability · Mathematics 2025-02-06 El Mehdi Haress , Alexandre Richard

In this paper, we study the asymptotic estimate of solution for a mixed-order time-fractional diffusion equation in a bounded domain subject to the homogeneous Dirichlet boundary condition. Firstly, the unique existence and regularity…

Analysis of PDEs · Mathematics 2021-08-26 Zhiyuan Li , Xinchi Huang , Masahiro Yamamoto

Fractional Brownian motion (FBM), a non-Markovian self-similar Gaussian stochastic process with long-ranged correlations, represents a widely applied, paradigmatic mathematical model of anomalous diffusion. We report the results of…

In this work, we are interested in building the fully discrete scheme for stochastic fractional diffusion equation driven by fractional Brownian sheet which is temporally and spatially fractional with Hurst parameters $H_{1}, H_{2}…

Numerical Analysis · Mathematics 2022-01-27 Daxin Nie , Jing Sun , Weihua Deng

In this work we construct compositions of processes of the form \bm{S}_n^{2\beta}(c^2 \mathpzc{L}^\nu (t) \r, t>0, \nu \in (0, 1/2], \beta \in (0,1], n \in \mathbb{N}, whose distribution is related to space-time fractional n-dimensional…

Probability · Mathematics 2013-12-23 Mirko D'Ovidio , Enzo Orsingher , Bruno Toaldo

Fractional calculus allows one to generalize the linear, one-dimensional, diffusion equation by replacing either the first time derivative or the second space derivative by a derivative of fractional order. The fundamental solutions of…

Statistical Mechanics · Physics 2007-05-23 Francesco Mainardi , Paolo Paradisi , Rudolf Gorenflo

We discuss the identification of a time-dependent potential in a time-fractional diffusion model from a boundary measurement taken at a single point. Theoretically, we establish a conditional Lipschitz stability for this inverse problem.…

Numerical Analysis · Mathematics 2024-07-23 Siyu Cen , Kwancheol Shin , Zhi Zhou

Fractional derivatives can be used to model time delays in a diffusion process. When the order of the fractional derivative is distributed over the unit interval, it is useful for modeling a mixture of delay sources. In some special cases…

Analysis of PDEs · Mathematics 2016-11-29 Jebessa B. Mijena , Erkan Nane

In this article, we prove Carleman estimates for the generalized time-fractional advection-diffusion equations by considering the fractional derivative as perturbation for the first order time-derivative. As a direct application of the…

Analysis of PDEs · Mathematics 2019-04-15 Zhiyuan Li , Xinchi Huang , Masahiro Yamamoto

Several classes of physical systems exhibit ultraslow diffusion for which the mean squared displacement at long times grows as a power of the logarithm of time ("strong anomaly") and share the interesting property that the probability…

Statistical Mechanics · Physics 2009-11-10 A. V. Chechkin , J. Klafter , I. M. Sokolov

We consider a 1-dimensional Brownian motion whose diffusion coefficient varies when it crosses the origin. We study the long time behavior and we establish different regimes, depending on the variations of the diffusion coefficient:…

Probability · Mathematics 2016-11-28 Nicolas Meunier , Clément Mouhot , Raphaël Roux

This paper studies the linear stochastic partial differential equation of fractional orders both in time and space variables $\left(\partial^\beta + \frac{\nu}{2} (-\Delta)^{\alpha/2} \right) u(t,x)= \lambda u(t,x) \dot{W}(t,x)$, where…

Probability · Mathematics 2016-02-19 Le Chen , Guannan Hu , Yaozhong Hu , Jingyu Huang