English
Related papers

Related papers: Determining the space dependent coefficients in sp…

200 papers

In this paper, we study a time-fractional subdiffusion equation with a nonlinear nonlocal initial condition involving the unknown solution at the final time. The considered problem is formulated using the Caputo fractional derivative of…

Analysis of PDEs · Mathematics 2025-06-25 Ravshan Ashurov , Rajapboy Saparboyev , Navbahor Nuraliyeva

The time-fractional diffusion equation is considered, where the time derivative is either of Caputo or Riemann-Liouville type. The solution of a general initial-boundary value problem with time-dependent boundary conditions over bounded and…

Analysis of PDEs · Mathematics 2023-01-04 M. Rodrigo

We consider a half-order time-fractional diffusion equation in an arbitrary dimension and investigate inverse problems of determining the source term or the diffusion coefficient from spatial data at an arbitrarily fixed time under some…

Analysis of PDEs · Mathematics 2020-10-21 X. Huang , A. Kawamoto

An adaptive finite difference scheme for variable-order fractional-time subdiffusion equations in the Caputo form is studied. The fractional time derivative is discretized by the L1 procedure but using nonhomogeneous timesteps. The size of…

Numerical Analysis · Mathematics 2024-09-20 Joaquín Quintana-Murillo , Santos Bravo Yuste

This paper is devoted to the study of generalised time-fractional evolution equations involving Caputo type derivatives. Using analytical methods and probabilistic arguments we obtain well-posedness results and stochastic representations…

Analysis of PDEs · Mathematics 2022-05-03 M. E. Hernández-Hernández , V. N. Kolokoltsov , L. Toniazzi

This article is devoted to presenting an abstract theory on time-fractional gradient flows for nonconvex energy functionals in Hilbert spaces. Main results consist of local and global in time existence of (continuous) strong solutions to…

Analysis of PDEs · Mathematics 2025-01-15 Goro Akagi , Yoshihito Nakajima

In this paper, we study both the direct and inverse random source problems associated with the multi-term time-fractional diffusion-wave equation driven by a fractional Brownian motion. Regarding the direct problem, the well-posedness is…

Analysis of PDEs · Mathematics 2023-11-03 Xiaoli Feng , Qiang Yao , Peijun Li , Xu Wang

In this paper, we develop two fast implicit difference schemes for solving a class of variable-coefficient time-space fractional diffusion equations with integral fractional Laplacian (IFL). The proposed schemes utilize the graded $L1$…

Numerical Analysis · Mathematics 2021-07-26 Xian-Ming Gu , Hai-Wei Sun , Yanzhi Zhang , Yong-Liang Zhao

The main objective of this paper is analysis of the initial-boundary value problems for the linear and semilinear time-fractional diffusion equations with a uniformly elliptic spatial differential operator of the second order and the Caputo…

Analysis of PDEs · Mathematics 2022-08-10 Yuri Luchko , Masahiro Yamamoto

We establish trace and extension theorems for evolutionary equations with the Caputo fractional derivatives in (weighted) $L_p$ spaces. To achieve this, we identify weighted Sobolev and Besov spaces with mixed norms that accommodate…

Analysis of PDEs · Mathematics 2023-08-28 Doyoon Kim , Kwan Woo

Tempered fractional diffusion equations are a crucial class of equations widely applied in many physical fields. In this paper, the Crank-Nicolson method and the tempered weighted and shifts Gr\"unwald formula are firstly applied to…

Numerical Analysis · Mathematics 2024-08-01 Xuan Zhang , Chaojie Wang , Haiyu Liu

In the present article, we study the diffusion equations with fractional time derivatives. The aim of this paper is to investigate the best possible regularity for the initial value/boundary value problems with non-homogeneous Dirichlet…

Analysis of PDEs · Mathematics 2015-01-08 Kenichi Fujishiro

In this paper, we develop a fast numerical method for solving the time-dependent Riesz space fractional diffusion equations with a nonlinear source term in the convex domain. An implicit finite difference method is employed to discretize…

Numerical Analysis · Mathematics 2021-02-24 Xin Huang , Hai-Wei Sun

In this work, an inverse problem in the fractional diffusion equation with random source is considered. The measurements used are the statistical moments of the realizations of single point data $u(x_0,t,\omega).$ We build the…

Analysis of PDEs · Mathematics 2020-04-09 Shubin Fu , Zhidong Zhang

A $g$--subdiffusion equation with fractional Caputo time derivative with respect to another function $g$ is used to describe a process of a continuous transition from subdiffusion with parameters $\alpha$ and $D_\alpha$ to subdiffusion with…

Statistical Mechanics · Physics 2022-05-25 Tadeusz Kosztołowicz , Aldona Dutkiewicz

We couple the L1 discretization for Caputo derivative in time with spectral Galerkin method in space to devise a scheme that solves quasilinear subdiffusion equations. Both the diffusivity and the source are allowed to be nonlinear…

Numerical Analysis · Mathematics 2022-11-30 Łukasz Płociniczak

An initial-boundary value problem for the time-fractional diffusion equation is discretized in space using continuous piecewise-linear finite elements on a polygonal domain with a re-entrant corner. Known error bounds for the case of a…

Numerical Analysis · Mathematics 2017-12-21 Kim Ngan Le , William McLean , Bishnu Lamichhane

We deal with the Cauchy problem for the space-time fractional diffusion-wave equation, which is obtained from the standard diffusion equation by replacing the second-order space derivative with a Riesz-Feller derivative of order alpha in…

Statistical Mechanics · Physics 2008-05-23 Francesco Mainardi , Yuri Luchko , Gianni Pagnini

This paper is dedicated to addressing the simultaneous inversion problem involving the initial value and space-dependent source term in a time-fractional diffusion-wave equation. Firstly, we establish the uniqueness of the inverse problem…

Numerical Analysis · Mathematics 2025-02-25 Yun Zhang , Xiaoli Feng , Xiongbin Yan

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