An extension of the landweber regularization for a backward time fractional wave problem
Langue
EN
Article de revue
Ce document a été publié dans
Discrete and Continuous Dynamical Systems - Series S. 2021-01-01, vol. 14, n° 8, p. 2893
Résumé en anglais
In this paper, we investigate numerical methods for a backward problem of the time-fractional wave equation in bounded domains. We propose two fractional filter regularization methods, which can be regarded as an extension ...Lire la suite >
In this paper, we investigate numerical methods for a backward problem of the time-fractional wave equation in bounded domains. We propose two fractional filter regularization methods, which can be regarded as an extension of the classical Landweber iteration for the time-fractional wave backward problem. The idea is first to transform the ill-posed backward problem into a weighted normal operator equation, then construct the regularization methods for the operator equation by introducing suitable fractional filters. Both a priori and a posteriori regularization parameter choice rules are investigated, together with an estimate for the smallest regularization parameter according to a discrepancy principle. Furthermore, an error analysis is carried out to derive the convergence rates of the regularized solutions generated by the proposed methods. The theoretical estimate shows that the proposed fractional regularizations efficiently overcome the well-known over-smoothing drawback caused by the classical regularizations. Some numerical examples are provided to confirm the theoretical results. In particular, our numerical tests demonstrate that the fractional regularization is actually more efficient than the classical methods for problems having low regularity.< Réduire
Mots clés en anglais
Backward problem
Time-fractional wave equation
Fractional filter regularization
Convergence
Project ANR
Méthode des champs : algorithmes et simulations de phénomènes complexes - ANR-16-CE40-0026
Initiative d'excellence de l'Université de Bordeaux - ANR-10-IDEX-0003
Initiative d'excellence de l'Université de Bordeaux - ANR-10-IDEX-0003
Unités de recherche