English
Related papers

Related papers: Fractional Fokker-Planck subdiffusion in alternati…

200 papers

A fractional reaction-diffusion equation is derived from a continuous time random walk model when the transport is dispersive. The exit from the encounter distance, which is described by the algebraic waiting time distribution of jump…

Statistical Mechanics · Physics 2009-11-10 Kazuhiko Seki , Mariusz Wojcik , M. Tachiya

We consider the $d=1$ nonlinear Fokker-Planck-like equation with fractional derivatives $\frac{\partial}{\partial t}P(x,t)=D \frac{\partial^{\gamma}}{\partial x^{\gamma}}[P(x,t) ]^{\nu}$. Exact time-dependent solutions are found for $ \nu =…

Statistical Mechanics · Physics 2009-02-06 Mauro Bologna , Constantino Tsallis , Paolo Grigolini

We consider a particle living in $\mathbb{R}_+$, whose velocity is a positive recurrent diffusion with heavy-tailed invariant distribution when the particle lives in $(0,\infty)$. When it hits the boundary $x=0$, the particle restarts with…

Probability · Mathematics 2023-10-24 Loïc Béthencourt

We investigate the behavior of the time derivatives of the solution to a linear time-fractional, advection-diffusion-reaction equation, allowing space- and time-dependent coefficients as well as initial data that may have low regularity.…

Analysis of PDEs · Mathematics 2020-03-24 William McLean , Kassem Mustapha , Raed Ali , Omar M. Knio

We consider the one-dimensional diffusion of a particle on a semi-infinite line and in a piecewise linear random potential. We first present a new formalism which yields an analytical expression for the Green function of the Fokker-Planck…

Disordered Systems and Neural Networks · Physics 2015-06-25 Petr Chvosta , Noelle Pottier

We derive, through subordination techniques, a generalized Feynman-Kac equation in the form of a time fractional Schrodinger equation. We relate such equation to a functional which we name the subordinated local time. We demonstrate through…

Statistical Mechanics · Physics 2023-05-01 Toby Kay , Luca Giuggioli

We derive the asymptotic first passage time (FPT) distribution for space-dependent variable-order time-fractional diffusion, where the fractional exponent $\alpha(x)$ varies with position. For any sufficiently smooth $\alpha(x)$ on a finite…

Statistical Mechanics · Physics 2026-04-16 Wancheng Li , Daniel S. Han

The foundations of the fractional diffusion equation are investigated based on coupled and decoupled continuous time random walks (CTRW). For this aim we find an exact solution of the decoupled CTRW, in terms of an infinite sum of stable…

Statistical Mechanics · Physics 2009-11-07 Eli Barkai

Einstein's explanation of Brownian motion provided one of the cornerstones which underlie the modern approaches to stochastic processes. His approach is based on a random walk picture and is valid for Markovian processes lacking long-term…

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

We discuss some applications of the Mittag-Leffler function and related probability distributions in the theory of renewal processes and continuous time random walks. In particular we show the asymptotic (long time) equivalence of a generic…

Probability · Mathematics 2010-04-27 Rudolf Gorenflo

Starting from the model of continuous time random walk, we focus our interest on random walks in which the probability distributions of the waiting times and jumps have fat tails characterized by power laws with exponent between 0 and 1 for…

Probability · Mathematics 2008-01-03 Rudolf Gorenflo , Entsar A. A. Abdel-Rehim

The Fokker-Planck Equation, applied to transport processes in fusion plasmas, can model several anomalous features, including uphill transport, scaling of confinement time with system size, and convective propagation of externally induced…

Plasma Physics · Physics 2007-11-05 D. F. Escande , F. Sattin

In inhomogeneous environments, the correct expression of the diffusive flux is often not given by the Fick's law $\Gamma = - D \nabla n $. The most general hydrodynamic equation modelling diffusion is indeed the Fokker-Planck Equation…

Plasma Physics · Physics 2009-03-18 F. Sattin

Diffusion in inhomogeneous materials can be described by both the Fick and Fokker--Planck diffusion equations. Here, we study a mixed Fick and Fokker-Planck diffusion problem with coefficients rapidly oscillating both in space and time. We…

Analysis of PDEs · Mathematics 2020-03-17 Micol Amar , Daniele Andreucci , Emilio N. M. Cirillo

Anomalous short- and long-time self-diffusion of non-overlapping fractal particles on a percolation cluster with spreading dimension $1.67(2)$ is studied by dynamic Monte Carlo simulations. As reported in Phys. Rev. Lett. 115, 097801…

Computational Physics · Physics 2020-10-08 Marco Heinen

The fractional diffusion equation is rigorously derived as a scaling limit from a deterministic Rayleigh gas, where particles interact via short range potentials with support of size $\varepsilon$ and the background is distributed in space…

Analysis of PDEs · Mathematics 2025-11-04 Karsten Matthies , Theodora Syntaka

Albeit the past intensive research, the governing equation of anomalous diffusion which is observed for the transport of particles underground is still an open problem. In this paper, as a governing equation, the advection-diffusion…

Analysis of PDEs · Mathematics 2025-05-27 Manabu Machida

In a very long Gaussian polymer on time scales shorter that the maximal relaxation time, the mean squared distance travelled by a tagged monomer grows as ~t^{1/2}. We analyze such sub-diffusive behavior in the presence of one or two…

Statistical Mechanics · Physics 2011-11-10 Yacov Kantor , Mehran Kardar

The problem of anomalous diffusion in momentum space is considered for plasma-like systems on the basis of a new collision integral, which is appropriate for consideration of the probability transition function (PTF) with long tails in…

Statistical Mechanics · Physics 2015-05-18 S. A. Trigger , W. Ebeling , G. J. F. van Heijst , P. P. J. M. Schram , I. M. Sokolov

In this paper, we study the long-time behaviour of solutions to the Vlasov-Fokker-Planck equation where the confining potential is non-convex. This is a nonlocal nonlinear partial differential equation describing the time evolution of the…

Analysis of PDEs · Mathematics 2017-08-03 Manh Hong Duong , Julian Tugaut