Abstract:
We consider some extremal problems of approximation theory of functions at the whole real axis R by entire functions of the exponential type. In particular, we find the exact values of the mean ν-widths of classes of functions, defined by the moduli of continuity of mth order ωm and majorants Ψ satisfying the special type of restriction.
Keywords:
best approximation, entire function of exponential type, modulus of continuity, mean ν-width, majorant.
Citation:
S. B. Vakarchuk, M. Sh. Shabozov, M. R. Langarshoev, “On the best mean square approximations by entire functions of exponential type in L2(R) and mean ν-widths of some functional classes”, Izv. Vyssh. Uchebn. Zaved. Mat., 2014, no. 7, 30–48; Russian Math. (Iz. VUZ), 58:7 (2014), 25–41
\Bibitem{VakShaLan14}
\by S.~B.~Vakarchuk, M.~Sh.~Shabozov, M.~R.~Langarshoev
\paper On the best mean square approximations by entire functions of exponential type in $L_2(\mathbb R)$ and mean $\nu$-widths of some functional classes
\jour Izv. Vyssh. Uchebn. Zaved. Mat.
\yr 2014
\issue 7
\pages 30--48
\mathnet{http://mi.mathnet.ru/ivm8909}
\transl
\jour Russian Math. (Iz. VUZ)
\yr 2014
\vol 58
\issue 7
\pages 25--41
\crossref{https://doi.org/10.3103/S1066369X14070032}
\scopus{https://www.scopus.com/record/display.url?origin=inward&eid=2-s2.0-84903692287}
Linking options:
https://www.mathnet.ru/eng/ivm8909
https://www.mathnet.ru/eng/ivm/y2014/i7/p30
This publication is cited in the following 6 articles:
T. E. Tileubayev, “Exact constants in Jackson–Stechkin inequality in L2 with a power-law weight”, Tr. IMM UrO RAN, 29, no. 1, 2023, 259–279
T. E. Tileubaev, “Tochnoe neravenstvo Dzheksona — Stechkina v L2,μα”, Chebyshevskii sb., 24:3 (2023), 139–161
S. B. Vakarchuk, “On Estimates in L2(R) of Mean ν-Widths of Classes of Functions Defined via the Generalized Modulus of Continuity of ωM”, Math. Notes, 106:2 (2019), 191–202
S. B. Vakarchuk, “Generalized characteristics of smoothness and some extremal problems in the approximation theory of functions in the space L2(R) . Ii”, Ukr. Math. J., 70:10 (2019), 1550–1584
S. B. Vakarchuk, “Generalized characteristics of smoothness and some extremal problems in the approximation theory of functions in the space L2(R) . I”, Ukr. Math. J., 70:9 (2019), 1345–1374
Sergey B. Vakarchuk, “Meansquare Approximation of Function Classes, Given on the all Real Axis R by the Entire Functions of Exponential Type”, IJARM, 6 (2016), 1