Computational identification of the minor coefficient of the anomalous subdiffusion equation

Computational identification of the minor coefficient of the anomalous subdiffusion equation

Vasil'ev V. I., Kardashevsky A. M.
Siberian Electronic Mathematical Reports, 22, 2, pp. A175-A185 (2024)

УДК 519.633.6 
DOI: 10.33048/semi.2025.22.002  
MSC 65M32


Abstract:

The article is devoted to the numerical solution of the nonlinear inverse problem of identifying the time-dependent junior coefficient of the differential equation of anomalous diffusion. The overdetermination condition is specified $\forall t\in (0,T]$ as a function value at an interior point of the domain, or as an integral of the solution over a spatial domain or part of it. An implicit difference scheme is constructed using the finite difference method. We close it with a discrete analog of the overdetermination condition, and as a result, we obtain a nonlinear system of algebraic equations. For its numerical implementation at each time layer, a non-iteration method based on decomposition into two systems of linear algebraic equations with a tridiagonal matrix is proposed. The results of the computational experiment on test problems showed a fairly high accuracy of the proposed method.

Keywords: Caputo fractional time derivative, anomalous diffusion equation, coefficient inverse problem, finite difference method, implicit difference scheme, decomposition method, computational experiment.