@Article{IJNAM-22-897, author = {Chen , MinghuaShi , Jiankang and Zhou , Zhi}, title = {Modified BDF2 Schemes for Subdiffusion Models with a Singular Source Term}, journal = {International Journal of Numerical Analysis and Modeling}, year = {2025}, volume = {22}, number = {6}, pages = {897--924}, abstract = {

The aim of this paper is to study the time stepping scheme for approximately solving the subdiffusion equation with a weakly singular source term. In this case, many popular time stepping schemes, including the correction of high-order BDF methods, may lose their high-order accuracy. To fill in this gap, in this paper, we develop a novel time stepping scheme, where the source term is regularized by using an $m$-fold integral-derivative and the equation is discretized by using a modified BDF2 convolution quadrature. We prove that the proposed time stepping scheme is second-order, even if the source term is nonsmooth in time and incompatible with the initial data. Numerical results are presented to support the theoretical results. The proposed approach is applicable for stochastic subdiffusion equation.

}, issn = {2617-8710}, doi = {https://doi.org/10.4208/ijnam2025-1039}, url = {http://global-sci.org/intro/article_detail/ijnam/24297.html} }