Galerkin finite element approximation of a stochastic semilinear fractional subdiffusion with fractionally integrated additive noise

A Galerkin finite element method is applied to approximate the solution of a semilinear stochastic space and time fractional subdiffusion problem with the Caputo fractional derivative of the order $ \alpha \in (0, 1)$, driven by fractionally integrated additive noise. After discussing the existence,...

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Bibliographic Details
Published in:IMA journal of numerical analysis Vol. 42; no. 3; pp. 2301 - 2335
Main Authors: Kang, Wenyan, Egwu, Bernard A, Yan, Yubin, Pani, Amiya K
Format: Journal Article
Language:English
Published: 22-07-2022
Online Access:Get full text
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Summary:A Galerkin finite element method is applied to approximate the solution of a semilinear stochastic space and time fractional subdiffusion problem with the Caputo fractional derivative of the order $ \alpha \in (0, 1)$, driven by fractionally integrated additive noise. After discussing the existence, uniqueness and regularity results, we approximate the noise with the piecewise constant function in time, in order to obtain a regularized stochastic fractional subdiffusion problem. The regularized problem is then approximated by using the finite element method in spatial direction. The mean squared errors are proved based on the sharp estimates of the various Mittag–Leffler functions involved in the integrals. Numerical experiments are conducted to show that the numerical results are consistent with the theoretical findings.
ISSN:0272-4979
1464-3642
DOI:10.1093/imanum/drab035