The Jacobi spectral collocation method for fractional integro-differential equations with non-smooth solutions

Abstract

<p style='text-indent:20px;'>In recent years, many numerical methods have been extended to fractional integro-differential equations. But most of them ignore an important problem. Even if the input function is smooth, the solutions of these equations would exhibit some weak singularity, which leads to non-smooth solutions, and a deteriorate order of convergence. To overcome this problem, we first study in detail the singularity of the fractional integro-differential equation, and then eliminate the singularity by introducing some smoothing transformation. We can maximize the convergence rate by adjusting the parameters in the auxiliary transformation. We use the Jacobi spectral-collocation method with global and high precision characteristics to solve the transformed equation. A comprehensive and rigorous error estimation under the <inline-formula><tex-math id="M2">$ L^{\infty} $</tex-math></inline-formula>- and <inline-formula><tex-math id="M3">$ L^{2}_{\omega^{\alpha, \beta}} $</tex-math></inline-formula>-norms is derived. Finally, we give specific numerical examples to show the accuracy of the theoretical estimation and the feasibility and effectiveness of the proposed method.</p>