Regularity Analysis and High-Order Time Stepping Scheme for Quasilinear Subdiffusion

Fuente: arXiv
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Auteurs principaux: Jin, Bangti, Quan, Qimeng, Wohlmuth, Barbara, Zhou, Zhi
Format: Preprint
Publié: 2024
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author Jin, Bangti
Quan, Qimeng
Wohlmuth, Barbara
Zhou, Zhi
author_facet Jin, Bangti
Quan, Qimeng
Wohlmuth, Barbara
Zhou, Zhi
contents In this work, we investigate a quasilinear subdiffusion model which involves a fractional derivative of order $α\in (0,1)$ in time and a nonlinear diffusion coefficient. First, using smoothing properties of solution operators for linear subdiffusion and a perturbation argument, we prove several pointwise-in-time regularity estimates that are useful for numerical analysis. Then we develop a high-order time stepping scheme for solving quasilinear subdiffusion, based on convolution quadrature generated by second-order backward differentiation formula with correction at the first step. Further, we establish that the convergence order of the scheme is $O(τ^{1+α-ε})$ without imposing any additional assumption on the regularity of the solution. The analysis relies on refined Sobolev regularity of the nonlinear perturbation remainder and smoothing properties of discrete solution operators. Several numerical experiments in two space dimensions show the sharpness of the error estimate.
format Preprint
id arxiv_https___arxiv_org_abs_2407_19146
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Regularity Analysis and High-Order Time Stepping Scheme for Quasilinear Subdiffusion
Jin, Bangti
Quan, Qimeng
Wohlmuth, Barbara
Zhou, Zhi
Numerical Analysis
In this work, we investigate a quasilinear subdiffusion model which involves a fractional derivative of order $α\in (0,1)$ in time and a nonlinear diffusion coefficient. First, using smoothing properties of solution operators for linear subdiffusion and a perturbation argument, we prove several pointwise-in-time regularity estimates that are useful for numerical analysis. Then we develop a high-order time stepping scheme for solving quasilinear subdiffusion, based on convolution quadrature generated by second-order backward differentiation formula with correction at the first step. Further, we establish that the convergence order of the scheme is $O(τ^{1+α-ε})$ without imposing any additional assumption on the regularity of the solution. The analysis relies on refined Sobolev regularity of the nonlinear perturbation remainder and smoothing properties of discrete solution operators. Several numerical experiments in two space dimensions show the sharpness of the error estimate.
title Regularity Analysis and High-Order Time Stepping Scheme for Quasilinear Subdiffusion
topic Numerical Analysis
url https://arxiv.org/abs/2407.19146