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This paper establishes explicit solutions for fractional diffusion problems on bounded domains. It also gives stochastic solutions, in terms of Markov processes time-changed by an inverse stable subordinator whose index equals the order of…

Probability · Mathematics 2016-04-22 Boris Baeumer , Tomasz Luks , Mark M. Meerschaert

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

We prove that the Hamilton Jacobi equation for an arbitrary Hamiltonian $H$ (locally Lipschitz but not necessarily convex) and fractional diffusion of order one (critical) has classical $C^{1,\alpha}$ solutions. The proof is achieved using…

Analysis of PDEs · Mathematics 2010-09-09 Luis Silvestre

The fractional differential equation $L^\beta u = f$ posed on a compact metric graph is considered, where $\beta>0$ and $L = \kappa^2 - \nabla(a\nabla)$ is a second-order elliptic operator equipped with certain vertex conditions and…

Numerical Analysis · Mathematics 2023-11-14 David Bolin , Mihály Kovács , Vivek Kumar , Alexandre B. Simas

We consider the divergent fractional Laplace operator presented in [Dipierro-Savin-Valdinoci, Rev. Mat. Iberoam.] and we prove three types of results. Firstly, we show that any given function can be locally shadowed by a solution of a…

Analysis of PDEs · Mathematics 2021-02-04 Serena Dipierro , Ovidiu Savin , Enrico Valdinoci

In this paper, we study equations driven by a non-local integrodifferential operator $\mathcal{L}_K$ with homogeneous Dirichlet boundary conditions. More precisely, we study the problem \[ \begin{aligned} &- \mathcal{L}_K u + V(x)u =…

Analysis of PDEs · Mathematics 2014-07-18 C. Grumiau , M. Squassina , C. Troestler

We study boundary regularity for the inhomogeneous Dirichlet problem for $2s$-stable operators in generalized H\"older spaces. Moreover, we provide explicit counterexamples that showcase the sharpness of our results. Our approach directly…

Analysis of PDEs · Mathematics 2025-10-02 Florian Grube

This paper develops a two-level fourth-order scheme for solving time-fractional convection-diffusion-reaction equation with variable coefficients subjected to suitable initial and boundary conditions. The basis properties of the new…

Numerical Analysis · Mathematics 2022-04-20 Eric Ngondiep

We study the two-dimensional Navier-Stokes equations forced by random noise with a diffusive term generalized via a fractional Laplacian that has a positive exponent strictly less than one. Because intermittent jets are inherently…

Analysis of PDEs · Mathematics 2022-06-24 Kazuo Yamazaki

We study the boundary regularity of solutions of the Dirichlet problem for the nonlocal operator with a kernel of variable orders. Since the order of differentiability of the kernel is not represented by a single number, we consider the…

Analysis of PDEs · Mathematics 2018-04-06 Minhyun Kim , Panki Kim , Jaehun Lee , Ki-Ahm Lee

This paper, which is the follow-up to part I, concerns the equation $(-\Delta)^{s} v+G'(v)=0$ in $\mathbb{R}^{n}$, with $s \in (0,1)$, where $(-\Delta)^{s}$ stands for the fractional Laplacian ---the infinitesimal generator of a L\'evy…

Analysis of PDEs · Mathematics 2011-11-04 Xavier Cabre , Yannick Sire

In this article we study the global regularity of 2D generalized magnetohydrodynamic equations (2D GMHD), in which the dissipation terms are $- \nu (- \triangle)^{\alpha} u$ and $- \kappa (-\triangle)^{\beta} b$. We show that smooth…

Analysis of PDEs · Mathematics 2013-02-28 Chuong V. Tran , Xinwei Yu , Zhichun Zhai

We study invariant solutions of a certain class of time-fractional diffusion-wave equations with variable coefficients via Lie symmetry analysis. In physics, the fractional diffusion equation describes transport dynamics that are governed…

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

The partial differential equation of Gaussian diffusion is generalized by using the time-fractional derivative of distributed order between 0 and 1, in both the Riemann-Liouville (R-L) and the Caputo (C) sense. For a general distribution of…

Statistical Mechanics · Physics 2008-05-27 Francesco Mainardi , Antonio Mura , Gianni Pagnini , Rudolf Gorenflo

This article study the fractional Hamiltonian systems \begin{eqnarray}\label{00} {_{t}}D_{\infty}^{\alpha}({_{-\infty}}D_{t}^{\alpha}u) + \lambda L(t)u = \nabla W(t, u), \;\;t\in \mathbb{R}, \end{eqnarray} where $\alpha \in (1/2, 1)$,…

Analysis of PDEs · Mathematics 2015-03-25 César E. Torres Ledesma

We study a porous medium equation with nonlocal diffusion effects given by an inverse fractional Laplacian operator. More precisely, $$ u_t=\nabla\cdot(u\nabla (-\Delta)^{-s}u), \quad \ 0<s<1. $$ The problem is posed in $\{x\in\ren, t\in…

Analysis of PDEs · Mathematics 2012-01-31 Luis Caffarelli , Fernando Soria , Juan Luis Vazquez

The fractional Fokker-Planck equation, which contains a variable diffusion coefficient, is discussed and solved. It corresponds to the L\'evy flights in a nonhomogeneous medium. For the case with the linear drift, the solution is stationary…

Statistical Mechanics · Physics 2009-06-09 Tomasz Srokowski

In this paper, we are concerned with the partial regularity of the suitable weak solutions to the fractional MHD equations in $\mathbb{R}^{n}$ for $n=2,\,3$. In comparison with the work of the 3D fractional Navier-Stokes equations obtained…

Analysis of PDEs · Mathematics 2016-09-21 Wei Ren , Yanqing Wang , Gang Wu

We discuss the derivation and the solutions of integro-differential equations (variable-order time-fractional diffusion equations) following as continuous limits for lattice continuous time random walk schemes with power-law waiting-time…

Statistical Mechanics · Physics 2020-07-22 Philipp Roth , Igor M. Sokolov