Abstract
In this paper, a high-order difference scheme is proposed for an one-dimensional space and time fractional Bloch–Torrey equation. A third-order accurate formula, based on the weighted and shifted Grünwald–Letnikov difference operators, is used to approximate the Caputo fractional derivative in temporal direction. For the discretization of the spatial Riesz fractional derivative, we approximate the weighed values of the Riesz fractional derivative at three points by the fractional central difference operator. The unique solvability, unconditional stability and convergence of the scheme are rigorously proved by the discrete energy method. The convergence order is 3 in time and 4 in space in L1(L2)-norm. Two numerical examples are implemented to testify the accuracy of the numerical solution and the efficiency of the difference scheme.
Funding source: National Natural Science Foundation of China
Award Identifier / Grant number: 11671081
Funding statement: The research is supported by National Natural Science Foundation of China (no. 11671081).
Acknowledgements
The authors would like to thank the editor and the reviewers for their helpful comments and valuable suggestions.
References
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