Abstract
Let \(L_{2,\mu}(\mathbb{R}^{2}), \ \mu(x,y)=\exp\{-(x^{2}+y^{2})\}, \ \mathbb{R}=(-\infty, +\infty), \ \mathbb{R}^{2}:=\mathbb{R}\times\mathbb{R},\) be the space of functions f, for which \(\mu^{1/2}f\in L_{2}(\mathbb{R}^{2}).\) In the metric of space \(L_{2,\mu}(\mathbb{R}^{2})\), the sharp inequalities of Jackson–Stechkin type are obtained, which relate the best mean-square approximation by “angle” of functions f from classes \(L_{2,\mu}^{r}(\mathbb{R}^{2})\) and the averaged with the weight q generalized mixed modules of continuity \(\Omega_{k,l}(D^{r}f)\), where
is the second order Chebyshev differential operator.
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The author thanks the referee for carefully reading the text of the paper and for useful comments, which led to a significant improvement in the presentation.
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Russian Text © The Author(s), 2021, published in Izvestiya Vysshikh Uchebnykh Zavedenii. Matematika, 2021, No. 9, pp. 3–12.
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Akobirshoev, M.O. Mean-Square Approximation by “Angle” in the Space \(L_{2,\mu}(\mathbb{R}^{2})\) with the Chebyshev–Hermite Weight. Russ Math. 65, 1–9 (2021). https://doi.org/10.3103/S1066369X21090012
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DOI: https://doi.org/10.3103/S1066369X21090012