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Anomalous diffusion is a phenomenon that cannot be modeled accurately by second-order diffusion equations, but is better described by fractional diffusion models. The nonlocal nature of the fractional diffusion operators makes substantially…

Numerical Analysis · Mathematics 2018-03-08 K. Mustapha , K. Furati , O. M. Knio , O. Le Maitre

In this paper, the one-dimensional time-fractional diffusion-wave equation with the fractional derivative of order $1 \le \alpha \le 2$ is revisited. This equation interpolates between the diffusion and the wave equations that behave quite…

Mathematical Physics · Physics 2016-01-14 Yuri Luchko , Francesco Mainardi , Yuriy Povstenko

Of primary interest in this paper is the numerical approximation of a time dependent fractional, in space, diffusion equation where the domain is assumed to be nonhomogeneous, having different axial diffusion coefficients. This work is…

Numerical Analysis · Mathematics 2026-05-12 T. Catoe , V. J. Ervin

We report new results about the anomalous diffusion of a particle in an aging medium. For each given age, the quasi-stationary particle velocity is governed by a generalized Langevin equation with a frequency-dependent friction coefficient…

Statistical Mechanics · Physics 2015-06-24 Noelle Pottier , Alain Mauger

A time-fractional Fokker-Planck initial-boundary value problem is considered, with differential operator $u_t-\nabla\cdot(\partial_t^{1-\alpha}\kappa_\alpha\nabla u-\textbf{F}\partial_t^{1-\alpha}u)$, where $0<\alpha <1$. The forcing…

Analysis of PDEs · Mathematics 2020-03-24 Kim-Ngan Le , William McLean , Martin Stynes

Fractional models and their parameters are sensitive to changes in the intrinsic micro-structures of anomalous materials. We investigate how such physics-informed models propagate the evolving anomalous rheology to the nonlinear dynamics of…

Numerical Analysis · Mathematics 2020-09-28 Jorge L. Suzuki , Pegah Varghaei , Ehsan Kharazmi , Mohsen Zayernouri

We derive equation describing distribution of energy losses of the particle propagating in fractal medium with quenched and dynamic heterogeneities. We show that in the case of the medium with fractal dimension $2<D<3$ the losses $\Delta$…

Statistical Mechanics · Physics 2015-05-28 Sergey Panyukov , Andrei Leonidov

Pulsed field gradient (PFG) has been increasingly employed to study anomalous diffusions in Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI). However, the analysis of PFG anomalous diffusion is complicated. In this…

Chemical Physics · Physics 2016-11-01 Guoxing Lin

In this paper, we study the existence of distributional solutions of the following non-local elliptic problem \begin{eqnarray*} \left\lbrace \begin{array}{l} (-\Delta)^{s}u + |\nabla u|^{p} =f \quad\text{ in } \Omega \qquad \qquad \qquad…

Analysis of PDEs · Mathematics 2020-06-03 Boumediene Abdellaoui , Pablo Ochoa , Ireneo Peral

Mass transport problems are ubiquitous in diverse fields of physics and engineering. With the development of fractional calculus, many have taken to studying problems of fractional mass transport either through numerical simulations or…

Mathematical Physics · Physics 2025-06-18 Nathaniel G. Hermann , M. Shane Hutson

A non--linear diffusion equation is derived by taking into account hopping rates depending on the occupation of next neighbouring sites. There appears additonal repulsive and attractive forces leading to a changed local mobiltiy. The…

Statistical Mechanics · Physics 2009-10-31 S. Artz , M. Schulz , S. Trimper

We study the relaxation process in normal and anomalous diffusion regimes for systems described by a generalized Langevin equation (GLE). We demonstrate the existence of a very general correlation function which describes the relaxation…

Disordered Systems and Neural Networks · Physics 2007-05-23 Mendeli H. Vainstein , Ismael V. L. Costa , Rafael Morgado , Fernando A. Oliveira

Normal diffusion in corrugated potentials with spatially uncorrelated Gaussian energy disorder famously explains the origin of non-Arrhenius $\exp[-\sigma^2/(k_BT^2)]$ temperature-dependence in disordered systems. Here we show that unbiased…

Statistical Mechanics · Physics 2014-09-24 Igor Goychuk , V. O. Kharchenko

The authors investigate the solution of a nonlinear reaction-diffusion equation connected with nonlinear waves. The equation discussed is more general than the one discussed recently by Manne, Hurd, and Kenkre (2000). The results are…

Classical Analysis and ODEs · Mathematics 2009-11-11 R. K. Saxena , A. M. Mathai , H. J. Haubold

In this letter, a theoretical method for the analysis of diffusive flux/current to limited scale self-affine random fractals is presented and compared with experimentally measured electrochemical current for such roughness. The theory…

Chemical Physics · Physics 2007-05-23 Rama Kant

In this paper, we consider the heat equation with the natural polynomial non-linear term; and with two different cases in the diffusion term. The first case (anomalous diffusion) concerns the fractional Laplacian operator with parameter…

Analysis of PDEs · Mathematics 2023-04-17 Oscar Jarrin , Geremy Loachamin

In this letter, we address the relationship between the statistical fluctuations of grain displacements for a full quasistatic plane shear experiment, and the corresponding anomalous diffusion exponent, $\alpha$. We experimentally validate…

Soft Condensed Matter · Physics 2015-12-09 Gaël Combe , Vincent Richefeu , Marta Stasiak , Allbens P. F. Atman

This article studies a Fokker-Planck type equation of fractional diffusion with conservative drift $\partial$f/$\partial$t = $\Delta$^($\alpha$/2) f + div(Ef), where $\Delta$^($\alpha$/2) denotes the fractional Laplacian and E is a…

Analysis of PDEs · Mathematics 2020-01-22 Laurent Lafleche

This paper studies a fractional attraction-repulsion system with generalized logistic source and nonlinear productions: \begin{equation*} \left\{ \begin{aligned} &u_t = -(-\Delta)^\alpha u - \chi_1 \nabla \cdot (u \nabla v) + \chi_2 \nabla…

Analysis of PDEs · Mathematics 2026-03-30 Liyan Song , Qingchun Li , Chengyuan Qu

For the fractional diffusion-wave equation with the Caputo-Dzhrbashyan fractional derivative of order $\alpha \in (1,2)$ with respect to the time variable, we prove an analog of the principle of limiting amplitude (well-known for the wave…

Analysis of PDEs · Mathematics 2014-05-13 Anatoly N. Kochubei