A Finite Difference Method with Non-uniform Timesteps for Fractional Diffusion Equations
Abstract
An implicit finite difference method with non-uniform timesteps for solving the fractional diffusion equation in the Caputo form is proposed. The method allows one to build adaptive methods where the size of the timesteps is adjusted to the behaviour of the solution in order to keep the numerical errors small without the penalty of a huge computational cost. The method is unconditionally stable and convergent. In fact, it is shown that consistency and stability implies convergence for a rather general class of fractional finite difference methods to which the present method belongs. The huge computational advantage of adaptive methods against fixed step methods for fractional diffusion equations is illustrated by solving the problem of the dispersion of a flux of subdiffusive particles stemming from a point source.
Cite
@article{arxiv.1109.6622,
title = {A Finite Difference Method with Non-uniform Timesteps for Fractional Diffusion Equations},
author = {Santos B. Yuste and Joaquín Quintana-Murillo},
journal= {arXiv preprint arXiv:1109.6622},
year = {2024}
}
Comments
This version correct some mistakes of the published version: superindex n-1 should be 0 in Eqs. (27), (28), (30) and (33), superindex m in the second line below Eq. (34) should be n; Eq.(34) is incorrect and must be removed; the reference to this equation in Sect. 4 must be changed to Eq. (33). The main results and conclusions of the paper are not affected by these corrections