arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2204.02015math.NAcs.NA
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求解次扩散方程的一种新的谱方法

A novel spectral method for the subdiffusion equation

Chuanju Xu, Wei Zeng

摘要:

本文设计并分析了求解次扩散方程的一种新的谱方法。众所周知,该方程的解在初始时刻附近通常是奇异的。因此,直接应用传统的高阶数值方法是低效的。我们试图克服这个困难,在一个新的方法,结合变量变换技术与谱方法。其想法是首先使用合适的变量变换来重新缩放基础方程,然后为重新缩放的方程构造谱方法。基于$ψ$ -分式索伯列夫空间建立了一个新的变分框架.这使我们能够证明相关的变分问题的适定性。提出的谱方法是基于变分问题和广义雅可比多项式来逼近重标度分数阶微分方程。我们的理论和数值研究表明,所提出的方法是指数收敛的一般右手边的功能,即使精确解具有非常有限的规律性。还提供了实施细节,以及一系列的数值例子来显示所提出的方法的效率。

英文摘要:

In this paper, we design and analyze a novel spectral method for the subdiffusion equation. As it has been known, the solutions of this equation are usually singular near the initial time. Consequently, direct application of the traditional high-order numerical methods is inefficient. We try to overcome this difficulty in a novel approach by combining variable transformation techniques with spectral methods. The idea is to first use suitable variable transformation to re-scale the underlying equation, then construct spectral methods for the re-scaled equation. We establish a new variational framework based on the $ψ$-fractional Sobolev spaces. This allows us to prove the well-posedness of the associated variational problem. The proposed spectral method is based on the variational problem and generalized Jacobi polynomials to approximate the re-scaled fractional differential equation. Our theoretical and numerical investigation show that the proposed method is exponentially convergent for general right hand side functions, even though the exact solution has very limited regularity. Implementation details are also provided, along with a series of numerical examples to show the efficiency of the proposed method.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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