TY - JOUR T1 - Fast Finite Difference Schemes for Time-Fractional Diffusion Equations with a Weak Singularity at Initial Time AU - Shen , Jin-Ye AU - Sun , Zhi-zhong AU - Du , Rui JO - East Asian Journal on Applied Mathematics VL - 4 SP - 834 EP - 858 PY - 2018 DA - 2018/10 SN - 8 DO - http://doi.org/10.4208/eajam.010418.020718 UR - https://global-sci.org/intro/article_detail/eajam/12821.html KW - Fractional differential equation, difference scheme, fast algorithm, singularity. AB -

A sharp estimate for the L1 formula on graded meshes, which approximates the Caputo derivatives of functions with a weak singularity at t = 0 is obtained. Combining such approximations with the sum-of-exponential approximations of the kernel, we develop fast difference schemes for one- and two-dimensional fractional diffusion equations, the solutions of which have a weak singularity at the starting time. The proof of the stability and convergence is based on the maximum principle. Numerical examples confirm theoretical estimates.