Abstract
Considering the approximation of a function \( f \) from a Sobolev space by the partial sums of Fourier series in a system of Sobolev orthogonal polynomials generated by classical Laguerre polynomials, we obtain an estimate for the convergence rate of the partial sums to \( f \).
References
Sharapudinov I.I., Gadzhieva Z.D., and Gadzhimirzaev R.M., “Systems of functions orthogonal with respect to scalar products of Sobolev type with discrete masses generated by classical orthogonal systems,” Dagestan Electr. Math. Reports, vol. 6, 31–60 (2016).
Sharapudinov I.I. and Magomed-Kasumov M.G., “On representation of a solution to the Cauchy problem by a Fourier Series in Sobolev-orthogonal polynomials generated by Laguerre polynomials,” Differ. Equ., vol. 54, no. 1, 49–66 (2018).
Gadzhimirzaev R.M., “On the uniform convergence of the Fourier series by the system of polynomials generated by the system of Laguerre polynomials,” Izv. Saratov Univ. Math. Mech. Inform., vol. 20, no. 4, 416–423 (2020).
Xu Y., “Approximation by polynomials in Sobolev spaces with Jacobi weight,” J. Fourier Anal. Appl., vol. 24, no. 6, 1438–1459 (2018).
Xu Y., Wang Z., and Li H., “Jacobi–Sobolev orthogonal polynomials and spectral methods for elliptic boundary value problems,” Commun. Appl. Math. Comput., vol. 1, no. 2, 283–308 (2019).
García-Ardila J.C. and Marriaga M.E., “Approximation by polynomials in Sobolev spaces associated with classical moment functionals,” Numer. Algor., 34 pp. (2023). doi 10.1007/s11075-023-01572-3
Leonardo E.F., Weighted Sobolev Orthogonal Polynomials and Approximation in the Ball. arXiv:2308.05469 (2023).
Szegö G., Orthogonal Polynomials, Amer. Math. Soc., Providence (1975).
Askey R. and Wainger S., “Mean convergence of expansions in Laguerre and Hermite series,” Amer. J. Math., vol. 87, no. 3, 695–708 (1965).
Muckenhoupt B., “Mean convergence of Hermite and Laguerre series. II,” Trans. Amer. Math. Soc., vol. 147, no. 2, 433–460 (1970).
Prudnikov A.P., Brychkov Yu.A., and Marichev O.I., Integrals and Series. Elementary Functions. Vol. 2, Fizmatlit, Moscow (2003) [Russian].
Gadzhimirzaev R.M. and Shakh-Emirov T.N., “Approximation properties of the Vallée-Poussin means of partial sums of a special series in Laguerre polynomials,” Math. Notes, vol. 110, no. 4, 475–488 (2021).
Dunford N. and Schwartz J.T., Linear Operators. Vol. 1: General Theory, John Wiley and Sons, New York (1988).
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This work was supported by ongoing institutional funding. No additional grants to carry out or direct this particular research were obtained.
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Translated from Sibirskii Matematicheskii Zhurnal, 2024, Vol. 65, No. 1, pp. 38–51. https://doi.org/10.33048/smzh.2024.65.104
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Gadzhimirzaev, R.M. On the Approximative Properties of Fourier Series in Laguerre–Sobolev Polynomials. Sib Math J 65, 30–43 (2024). https://doi.org/10.1134/S003744662401004X
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DOI: https://doi.org/10.1134/S003744662401004X