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In this article, we consider the reconstruction of $\rho(t)$ in the (time-fractional) diffusion equation $(\partial_t^\alpha-\triangle)u(x,t)=\rho(t)g(x)$ ($0<\alpha \le 1$) by the observation at a single point $x_0$. We are mainly…

Analysis of PDEs · Mathematics 2017-08-02 Yikan Liu , Zhidong Zhang

We consider a time dependent problem generated by a nonlocal operator in space. Applying a discretization scheme based on $hp$-Finite Elements and a Caffarelli-Silvestre extension we obtain a semidiscrete semigroup. The discretization in…

Numerical Analysis · Mathematics 2024-07-25 Jens Markus Melenk , Alexander Rieder

A one dimensional fractional diffusion model with the Riemann-Liouville fractional derivative is studied. First, a second order discretization for this derivative is presented and then an unconditionally stable weighted average finite…

Numerical Analysis · Mathematics 2011-09-13 Ercília Sousa , Can Li

We relate the convergence of time-changed processes driven by fractional equations to the convergence of corresponding Dirichlet forms. The fractional equations we dealt with are obtained by considering a general fractional operator in…

Probability · Mathematics 2019-10-24 Raffaela Capitanelli , Mirko D'Ovidio

In this paper we develop a reduction procedure for determining exact wave solutions of first order quasilinear hyperbolic one-dimensional nonhomogeneous systems. The approach is formulated within the theoretical framework of the method of…

Mathematical Physics · Physics 2025-07-22 Alessandra Jannelli , Natale Manganaro , Alessandra Rizzo

In this paper, we consider an inverse problem for a time-fractional diffusion equation with a nonlinear source. We prove that the considered problem is ill-posed, i.e. the solution does not depend continuously on the data. The problem is…

Analysis of PDEs · Mathematics 2019-10-09 Tran Bao Ngoc , Nguyen Huy Tuan , Mokhtar Kirane

In mathematical modeling of the non-squared frequency-dependent diffusions, also known as the anomalous diffusions, it is desirable to have a positive real Fourier transform for the time derivative of arbitrary fractional or odd integer…

Computational Engineering, Finance, and Science · Computer Science 2007-05-23 W Chen

In this paper, we investigate direct and inverse problems for the time-fractional heat equation with a time-dependent leading coefficient for positive operators. First, we consider the direct problem, and the unique existence of the…

Analysis of PDEs · Mathematics 2023-06-14 Daurenbek Serikbaev , Michael Ruzhansky , Niyaz Tokmagambetov

We prove sharp estimates for the decay in time of solutions to a rather general class of non-local in time subdiffusion equations on a bounded domain subject to a homogeneous Dirichlet boundary condition. Important special cases are the…

Analysis of PDEs · Mathematics 2013-10-02 Vicente Vergara , Rico Zacher

In this paper, we suggest a new heterogeneous multiscale method (HMM) for the time-harmonic Maxwell equations in locally periodic media. The method is constructed by using a divergence-regularization in one of the cell problems. This allows…

Numerical Analysis · Mathematics 2015-09-15 Patrick Henning , Mario Ohlberger , Barbara Verfürth

Fractional, anomalous diffusion in space-periodic potentials is investigated. The analytical solution for the effective, fractional diffusion coefficient in an arbitrary periodic potential is obtained in closed form in terms of two…

Statistical Mechanics · Physics 2021-02-02 E. Heinsalu , M. Patriarca , I. Goychuk , P. Hanggi

This paper is concerned with the mathematical analysis of the inverse random source problem for the time fractional diffusion equation, where the source is assumed to be driven by a fractional Brownian motion. Given the random source, the…

Analysis of PDEs · Mathematics 2020-04-22 Xiaoli Feng , Peijun Li , Xu Wang

We study solution techniques for parabolic equations with fractional diffusion and Caputo fractional time derivative, the latter being discretized and analyzed in a general Hilbert space setting. The spatial fractional diffusion is realized…

Numerical Analysis · Mathematics 2015-03-05 Ricardo H. Nochetto , Enrique Otarola , Abner J. Salgado

In this paper, a non-uniform time-stepping convex-splitting numerical algorithm for solving the widely used time-fractional Cahn-Hilliard equation is introduced. The proposed numerical scheme employs the $L1^+$ formula for discretizing the…

Numerical Analysis · Mathematics 2020-06-04 Jun Zhang , Jia Zhao , JinRong Wang

Difference schemes for the time-fractional diffusion equation with variable coefficients and nonlocal boundary conditions containing real parameters $\alpha$ and $\beta$ are considered. By the method of energy inequalities, for the solution…

Numerical Analysis · Mathematics 2015-03-27 A. A. Alikhanov

In this paper, the theory of the fractional singular Lagrangian systems is investigated with second order derivatives. The fractional quantization for these systems is examined using the WKB approximation. The Hamilton Jacobi treatment can…

General Mathematics · Mathematics 2023-01-20 Eyad Hasan Hasan

This study presents a novel high-order numerical method designed for solving the two-dimensional time-fractional convection-diffusion (TFCD) equation. The Caputo definition is employed to characterize the time-fractional derivative. A weak…

Numerical Analysis · Mathematics 2023-08-21 Anshima Singh , Sunil Kumar

We study the periodic homogenization of convex Hamilton-Jacobi equations on perforated domains with Dirichlet boundary conditions. By analyzing the optimal control representation of the solutions and the properties of the metric function…

Analysis of PDEs · Mathematics 2025-11-03 Yuxi Han , Son Tu

We consider a class of nonlinear fractional equations having the Caputo fractional derivative of the time variable $t$, the fractional order of the self-adjoint positive definite unbounded operator in a Hilbert space and a singular…

Analysis of PDEs · Mathematics 2020-02-18 Nguyen Minh Dien , Erkan Nane , Dang Duc Trong

We investigate in this work a fully-discrete semi-Lagrangian approximation of second order possibly degenerate Hamilton-Jacobi-Bellman (HJB) equations on a bounded domain with oblique boundary conditions. These equations appear naturally in…

Numerical Analysis · Mathematics 2021-09-22 Elisa Calzola , Elisabetta Carlini , Xavier Dupuis , Francisco J. Silva
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