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JOURNALS // Sibirskii Matematicheskii Zhurnal // Archive

Sibirsk. Mat. Zh., 2025 Volume 66, Number 5, Pages 828–837 (Mi smj7981)

This article is cited in 1 paper

Uniform and absolute convergence of the Fourier series in Hermite–Sobolev polynomials

R. M. Gadzhimirzaev

Dagestan Federal Research Center of the Russian Academy of Sciences, Makhachkala, Russia

Abstract: We study a system of polynomials orthonormal with respect to a Sobolev-type inner product and associated with classical Hermite polynomials. It is shown that for functions from a weighted Sobolev space the Fourier series in this system converges uniformly on an interval provided that the parameter $p$ is not less than two. For the cases where $p$ is less than two, we construct an example of a function whose Fourier series diverges at a given point. We also investigate the question of absolute convergence of the Fourier series in this system of polynomials on an interval.

Keywords: Hermite–Sobolev polynomials, Fourier series, uniform convergence, absolute convergence.

UDC: 517.521.2

MSC: 35R30

Received: 19.06.2025
Revised: 23.07.2025
Accepted: 27.07.2025

DOI: 10.33048/smzh.2025.66.505


 English version:
Siberian Mathematical Journal, 2025, 66:5, 1149–1157


© Steklov Math. Inst. of RAS, 2026