A Fast Temporal Second Order Difference Scheme for the Fractional Sub-Diffusion Equations on One Dimensional Space Unbounded Domain

A Fast Temporal Second Order Difference Scheme for the Fractional Sub-Diffusion Equations on One Dimensional Space Unbounded Domain

Year:    2023

Author:    Ren-Jun Qi, Zhi-Zhong Sun

Journal of Mathematical Study, Vol. 56 (2023), Iss. 2 : pp. 173–205

Abstract

The numerical solution of the fractional sub-diffusion equations on one dimensional space unbounded domain is considered. Based on the high-order local artificial boundary conditions proposed in [Zhang W., et al., J. Math. Study., 2017, 50(1): 28-53], the original space unbounded problem can be reformulated to an initial-boundary value problem on a bounded computational domain. By Alikhanov’s $L2-1_σ$ formula and sum-of-exponentials approximation, a fast temporal second order difference scheme for the reduced problem is presented. The unique solvability, stability and convergence order $O(τ^2+h^2 )$ of the proposed method are proved by means of energy method, where $τ$ and $h$ denote the time and space step sizes, respectively. Some numerical examples are included to validate the theoretical results. To the best of our knowledge, this is the first work that combines the high order numerical method with the artificial boundary method for the time fractional diffusion problems on spatial unbounded domains.

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/10.4208/jms.v56n2.23.05

Journal of Mathematical Study, Vol. 56 (2023), Iss. 2 : pp. 173–205

Published online:    2023-01

AMS Subject Headings:   

Copyright:    COPYRIGHT: © Global Science Press

Pages:    33

Keywords:    Fractional sub-diffusion equations space unbounded domain high-order local artificial boundary conditions difference scheme fast algorithm energy method.

Author Details

Ren-Jun Qi

Zhi-Zhong Sun