Sharp Pointwise-in-Time Error Estimate of L1 Scheme for Nonlinear Subdiffusion Equations

Sharp Pointwise-in-Time Error Estimate of L1 Scheme for Nonlinear Subdiffusion Equations

Year:    2024

Author:    Dongfang Li, Hongyu Qin, Jiwei Zhang

Journal of Computational Mathematics, Vol. 42 (2024), Iss. 3 : pp. 662–678

Abstract

An essential feature of the subdiffusion equations with the $α$-order time fractional derivative is the weak singularity at the initial time. The weak regularity of the solution is usually characterized by a regularity parameter $σ ∈ (0, 1) ∪ (1, 2).$ Under this general regularity assumption, we present a rigorous analysis for the truncation errors and develop a new tool to obtain the stability results, i.e., a refined discrete fractional-type Grönwall inequality (DFGI). After that, we obtain the pointwise-in-time error estimate of the widely used L1 scheme for nonlinear subdiffusion equations. The present results fill the gap on some interesting convergence results of L1 scheme on $σ ∈ (0, α) ∪ (α, 1) ∪ (1, 2].$ Numerical experiments are provided to demonstrate the effectiveness of our theoretical analysis.

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Journal Article Details

Publisher Name:    Global Science Press

Language:    English

DOI:    https://doi.org/10.4208/jcm.2205-m2021-0316

Journal of Computational Mathematics, Vol. 42 (2024), Iss. 3 : pp. 662–678

Published online:    2024-01

AMS Subject Headings:   

Copyright:    COPYRIGHT: © Global Science Press

Pages:    17

Keywords:    Sharp pointwise-in-time error estimate L1 scheme Nonlinear subdiffusion equations Non-smooth solutions.

Author Details

Dongfang Li

Hongyu Qin

Jiwei Zhang