Abstract
The paper investigates an inverse problem for finding the order of the fractional derivative in the sense of Gerasimov–Caputo in the wave equation with an arbitrary positive self-adjoint operator \(A\) having a discrete spectrum. By means of the classical Fourier method, it is proved that the value of the projection of the solution onto some eigenfunction at a fixed time uniquely restores the order of the derivative. Several examples of the operator \(A\) are discussed, including a linear system of fractional differential equations, fractional Sturm–Liouville operators, and many others.
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Acknowledgments
The author wish to express gratitude to S. A. Alimov for discussing the results in this paper. The authors are also grateful to the anonymous referee of the journal for his/her comments, which have significantly improved the content of this paper.
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Translated from Matematicheskie Zametki, 2021, Vol. 110, pp. 824–836 https://doi.org/10.4213/mzm13090.
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Ashurov, R.R., Faiziev, Y.É. Inverse Problem for Finding the Order of the Fractional Derivative in the Wave Equation. Math Notes 110, 842–852 (2021). https://doi.org/10.1134/S0001434621110213
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DOI: https://doi.org/10.1134/S0001434621110213