Abstract
Estimates that are accurate by order of magnitude have been obtained for some characteristics of the linear and nonlinear approximations of the isotropic classes of the Nikol’skii–Besov-type \({\mathbf{B}}_{p,\theta }^{\omega }\) of periodic functions of several variables in the spaces Bq,1, 1 ≤ q ≤ ∞. A specific feature of those spaces, as linear subspaces of Lq, is that the norm in them is “stronger” than the Lq-norm.
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References
V. N. Temlyakov, “Estimates of the asymptotic characteristics of classes of functions with bounded mixed derivative or difference,” Tr. Mat. Inst. Steklova, 189, 138–168 (1989).
B. S. Kashin and V. N. Temlyakov, “On the best m-term approximations and entropy of sets in the space L1,” Mat. notes, 56(5), 57–86 (1994).
E. S. Belinsky, “Estimates of entropy numbers and Gaussian measures for classes of functions with bounded mixed derivative,” J. Approxim. Theory, 93, 114–127 (1998).
A. S. Romanyuk, “Entropy numbers and widths of the classes \({B}_{p,\theta }^{r}\) of periodic functions of several variables,” Ukr. Mat. Zhurn., 68(10), 1403–1417 (2016).
A. S. Romanyuk and V. S. Romanyuk, “Approximation characteristics of the classes of periodic functions of several variables in the space B∞,1,” Ukr. Mat. Zhurn., 71(2), 271–278 (2019).
A. S. Romanyuk and V. S. Romanyuk, “Estimates of some approximation characteristics of the classes of periodic functions of several variables,” Ukr. Mat. Zhurn., 71 (8), 1102–1115 (2019).
A. S. Romanyuk and V. S. Romanyuk, “Approximation characteristics and properties of the best approximation operators for the classes of functions from the Sobolev and Nikol’skii–Besov spaces,” Ukr. Mat. Visn., 17(3), 372–395 (2020).
A. S. Romanyuk and S. Ya. Yanchenko, “Estimates of approximation characteristics and properties of the best approximation operators of the classes of periodic functions in the space B1,1,” Ukr. Mat. Zhurn., 73(8), 1102–1119 (2021).
M. V. Hembars’kyi and S. B. Hembars’ka, “Widths of the classes of periodic functions of many variables in the space B1,1,” Ukr. Mat. Visn., 15(1), 43–57 (2018).
M. V. Hembars’kyi, S. B. Hembars’ka, and K. V. Solich, “The best approximations and widths of the classes of periodic functions of one and several variables in the space B∞,1,” Mathematical Studies, 51(1), 74–85 (2019).
O. V. Fedunyk-Yaremchuk, M. V. Hembars’kyi, and S. B. Hembars’ka, “Approximative characteristics of the Nikol’skii–Besov-type classes of periodic functions in the space B∞,1,” Carpathian Math. Publ., 12(2), 376–391 (2020).
Xu. Guiqiao, “The n-widths for generalized periodic Besov classes,” Acta Math. Sci., 25(4), 663–671 (2005).
A. S. Romanyuk, Approximation of the isotropic classes of periodic functions of several variables in the space Lq. In: Theory of Function Approximation and Related Issues: Proceedings of the Institute of Mathematics of the National Academy of Sciences of Ukraine, 5(1), 263–278 (2008).
A. S. Romanyuk, “Approximation characteristics of the isotropic classes of periodic functions of several variables,” Ukr. Mat. Zhurn., 61(4), 513–523 (2009).
S. P. Voitenko, “The best M-term trigonometric approximations of the classes \({B}_{p,\theta }^{\Omega }\) of periodic functions of several variables,” Ukr. Mat. Zhurn., 61(9), 1189–1199 (2009).
S. P. Voitenko, “The best orthogonal trigonometric approximations of the classes \({B}_{p,\theta }^{\Omega }\) of periodic functions of several variables,” Ukr. Mat. Zhurn., 61(11), 1473–1484 (2009).
S. A. Stasyuk, “Approximation of the classes \({B}_{p,\theta }^{\upomega }\) of periodic functions of several variables by polynomials with the spectrum in cubic domains,” Mathematical studies, 35(1), 66–73 (2011).
N. V. Derev’yanko, “Trigonometric widths of the classes of periodic functions of many variables,” Ukr. Mat. Zhurn., 64(8), 1041–1052 (2012).
K. V. Solich, “Kolmogorov widths of the classes \({B}_{p,\theta }^{\upomega }\) of periodic functions of several variables in the space Lq,” Ukr. Mat. Zhurn., 64(10), 1416–1425 (2012).
N. K. Bari and S. B. Stechkin, “The best approximations and differential properties of two conjugate functions,” Trudy Mat. Inst. Akad. Nauk SSSR, 5, 483–522 (1956).
O. V. Besov, “Study of a family of functional spaces in connection with the embedding and extension theorems,” Tr. Mat. Inst. Steklova, 60, 42–61 (1961).
S. M. Nikol’skii, “Inequalities for the entire functions of finite degree and their application in the theory of differentiable functions of several variables,” Tr. Mat. Inst. Steklova, 38, 244–278 (1951).
Liu Yongping and Xu Guiqiao. “The infinite-dimensional widths and optimal recovery of generalized Besov classes,” J. Complexity, 18(3), 815–832 (2002).
E. S. Belinsky, Approximation by a “floating” system of exponents on the classes of periodic functions with limited mixed derivative. In: Research on the theory of functions of several real variables. Yaroslavl: Yaroslavl Univ. (in Russian), 16–33 (1988).
A. S. Romanyuk, “Approximation of the classes of periodic functions of several variables,” Mat. notes, 71(1), 109–121 (2002).
A. S. Romanyuk, “Bilinear and trigonometric approximations of the Besov classes \({B}_{p,\theta }^{r}\) of periodic functions of several variables,” Izvest. RAN. Ser. Mat., 70(2), 69–98 (2006).
A. S. Romanyuk, “The best trigonometric approximations of the classes of periodic functions of several variables in the uniform metric,” Mat. notes, 82(2), 247–261 (2007).
A. S. Romanyuk, “The best trigonometric and bilinear approximations of the classes of functions of several variables,” Mat. notes, 94(3), 379–391 (2013).
A. S. Serdyuk and T. A. Stepaniuk, “Order estimates for the best orthogonal trigonometric approximations of the classes of convolutions of periodic functions of low smoothness,” Ukr. Mat. Zhurn., 67(7), 916–936 (2015).
A. S. Romanyuk, Approximation characteristics of the classes of periodic functions of several variables. In: Proceedings of the Institute of Mathematics of the National Academy of Sciences of Ukraine, 93 (in Russian), p. 352 (2012).
V. N. Temlyakov, Approximation of periodic functions. New York, Nova Sc. Publ. Inc., 1993.
S. B. Hembars’ka and P. V. Zaderei, “Best orthogonal trigonometric approximation of the classes of the Nikol’skii-Besov-type of periodic functions in the space B∞,1,” Ukr. Mat. Zhurn., 74(6), 784–795 (2022).
O. V. Fedunyk-Yaremchuk and S. B. Hembars’ka, “Best orthogonal trigonometric approximations of the Nikol’skii-Besov-type classes of periodic functions of one and several variables,” Carpathian Math. Publ., 14(1), 171–184 (2022).
A. S. Romanyuk, V. S. Romanyuk, K. V. Pozhars’ka, and S. B. Hembars’ka, “Characteristics of linear and nonlinear approximation of isotropic classes of periodic multivariate functions,” Carpathian Math. Publ., 15 (1), 78–94 (2023).
A. S. Romanyuk and S. Ya. Yanchenko, “Approximation of classes of periodic functions of one and several variables from the Nikol’skii–Besov and Sobolev spaces,” Ukr. Mat. Zhurn., 74(6), 844–855 (2022).
S. B. Stechkin, “On the absolute convergence of orthogonal series,” Dokl. Akad. Nauk SSSR, 102(1), 37–40 (1955).
R. S. Ismagilov, “Diameters of sets in normed linear spaces and the approximation of functions by trigonometric polynomials,” Usp. Mat. Nauk, 29(3), 161–178 (1974).
R. A. De Vore and V. N. Temlyakov, “Nonlinear approximation by trigonometric sums,” J. Fourier Anal. Appl., 2(2), 29–40 (1995).
A. S. Romanyuk, “The best M-term trigonometric approximations of the Besov classes of periodic functions of several variables,” Izvest. RAN. Ser. Mat., 67(2), 61–100 (2003).
R. M. Trigub and E. S. Belinsky, Fourier Analysis and Approximation of Functions. Kluwer Academic Publishers, 2004.
V. N. Temlyakov, Multivariate approximation. Cambridge University Press, 2018.
D. Dũng, V. Temlyakov, and T. Ullrich, Hyperbolic cross approximation. Adv. Courses Math. Birkhäuser, CRM Barselona, 2019.
A. N. Kolmogorov, “Über die beste Annäherung von Funkctionen einer Funktionenklasse,” Ann. Math., 37, 107–111 (1936).
V. M. Tikhomirov, “Diameters of sets in function spaces and the theory of best approximations,” Usp. Mat. Nauk, 15(3), 81–120 (1960).
E. S. Belinsky and E. M. Galeev, “On the minimum of norms of mixed derivatives of trigonometric polynomials with given number of harmonics,” Vestn. MGU Ser.1. Mat., Mekh., (2), 3–7 (1991).
A. S. Romanyuk and V. S. Romanyuk, “Trigonometric and orthoprojection widths of the classes of periodic functions of many variables,” Ukr. Mat. Zhurn., 61(10), 1348–1366 (2009).
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Presented by R. M. Trygub
Translated from Ukrains’kiĭ Matematychnyĭ Visnyk, Vol. 20, No. 2, pp. 161–185, April–June, 2
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Hembars’ka, S.B., Romanyuk, I.A. & Fedunyk-Yaremchuk, O.V. Characteristics of the linear and nonlinear approximations of the Nikol’skii–Besov-type classes of periodic functions of several variables. J Math Sci 274, 307–326 (2023). https://doi.org/10.1007/s10958-023-06602-y
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DOI: https://doi.org/10.1007/s10958-023-06602-y