Improved Error Estimates of a Finite Difference/Spectral Method for Time-Fractional Diffusion Equations

Improved Error Estimates of a Finite Difference/Spectral Method for Time-Fractional  Diffusion Equations

Year:    2015

International Journal of Numerical Analysis and Modeling, Vol. 12 (2015), Iss. 2 : pp. 384–400

Abstract

In this paper, we first consider the numerical method that Lin and Xu proposed and analyzed in [Finite difference/spectral approximations for the time-fractional diffusion equation, JCP 2007] for the time-fractional diffusion equation. It is a method based on the combination of a finite different scheme in time and spectral method in space. The numerical analysis carried out in that paper showed that the scheme is of $(2-\alpha)$-order convergence in time and spectral accuracy in space for smooth solutions, where $\alpha$ is the time-fractional derivative order. The main purpose of this paper consists in refining the analysis and providing a sharper estimate for both time and space errors. More precisely, we improve the error estimates by giving a more accurate coefficient in the time error term and removing the factor in the space error term, which grows with decreasing time step. Then the theoretical results are validated by a number of numerical tests.

You do not have full access to this article.

Already a Subscriber? Sign in as an individual or via your institution

Journal Article Details

Publisher Name:    Global Science Press

Language:    English

DOI:    https://doi.org/2015-IJNAM-495

International Journal of Numerical Analysis and Modeling, Vol. 12 (2015), Iss. 2 : pp. 384–400

Published online:    2015-01

AMS Subject Headings:    Global Science Press

Copyright:    COPYRIGHT: © Global Science Press

Pages:    17

Keywords:    Error estimates finite difference methods spectral methods time fractional diffusion equation.