Abstract
We establish direct estimates of the rate of weighted simultaneous approximation by the Szász–Mirakjan operator for smooth functions in the supremum norm on the non-negative semi-axis. We consider Jacobi-type weights. The estimates are stated in terms of appropriate moduli of smoothness or K-functionals.
Similar content being viewed by others
References
T. Acar, A. Aral, I. Raşa, The new forms of Voronovskaya’s theorem in weighted spaces. Positivity 20(1), 25–40 (2016)
T. Acar, A. Aral, I. Raşa, Approximation by \(k\)-th order modifications of Szász-Mirakyan operators. Studia Sci. Math. Hungar. 53(3), 379–398 (2016)
A. Aral, G. Tachev, Quantitative Voronovskaya type theorems for a general sequence of linear positive operators. Filomat 33(8), 2507–2518 (2019)
P.L. Butzer, On the extensions of Bernstein polynomials to the infinite interval. Proc. Am. Math. Soc. 5, 547–553 (1954)
P.L. Butzer, H. Karsli, Voronovskaya-type theorems for derivatives of the Bernstein–Chlodowsky polynomials and the Szász-Mirakyan operator. Comm. Math. 49(1), 33–58 (2009)
R.A. DeVore, G.G. Lorentz, Constructive Approximation (Springer, Berlin, 1993)
Z. Ditzian, V. Totik, Moduli of Smoothness (Springer, New York, 1987)
B.R. Draganov, Strong estimates of the weighted simultaneous approximation by the Bernstein and Kantorovich operators and their iterated Boolean sums. J. Approx. Theory 200, 92–135 (2015)
B.R. Draganov, I. Gadjev, Approximation of functions by the Szász-Mirakjan–Kantorovich Operator. Numer. Funct. Anal. Optim. 40, 803–824 (2019)
B.R. Draganov, K.G. Ivanov, Natural weights for uniform approximation by the Szász–Mirakjan operator, in Proceedings of International Conference on “Constructive Theory of Functions”, Sozopol 2013: Dedicated to Blagovest Sendov and to the memory of Vasil Popov, ed. by K. Ivanov, G. Nikolov, R. Uluchev (Prof. Marin Drinov Academic Publishing House, Sofia, 2014), pp. 57–72
J. Favard, Sur les multiplicateurs d’interpolation. J. Math. Pure Appl. 23(9), 219–247 (1944)
I. Gadjev, About characterization of one K-functional. J. Math. Anal. Appl. 450, 1076–1082 (2017)
I. Gadjev, P.E. Parvanov, Weighted approximation of functions in \(L_\infty [0,\infty )\). Mediterr. J. Math. 14, 220 (2017)
I. Gadjev, P.E. Parvanov, R. Uluchev, Weighted approximation by Kantorovich type modification of Meyer–König and Zeller operator. Ann. Sofia Univ., Fac. Math. Inf. 105, 75–95 (2018)
V. Gupta, G. Tachev, General form of Voronovskaja’s theorem in terms of weighted modulus of continuity. Results Math. 69(3–4), 419–430 (2016)
V. Gupta, G. Tachev, Approximation with Positive Linear Operators and Linear Combinations (Springer, Berlin, 2017)
H.B. Knoop, P. Pottinger, On simultaneous approximation by certain linear positive operators. Arch. Math. 48, 511–520 (1987)
A.-J. López-Moreno, Weighted simultaneous approximation with Baskakov type operators. Acta Math. Hungar. 104(1–2), 143–151 (2004)
R. Martini, On the approximation of functions together with their derivatives by certain linear positive operators. Indag. Math. 31, 473–481 (1969)
G.M. Mirakjan, Approximation of continuous functions with the aid of polynomials (Russian). Dokl. Akad. Nauk SSSR 31, 201–205 (1941)
S.P. Singh, On the degree of approximation by Szász operators. Bull. Austral. Math. Soc. 24(2), 221–225 (1981)
X.-H. Sun, On the simultaneous approximation of functions and their derivatives by the Szász-Mirakyan operator. J. Approx. Theory 55, 279–288 (1988)
X.-H. Sun, On the simultaneous approximation of functions and their derivatives by the Szász-Mirakyan operator (II). Stud. Appl. Math. 89(3), 189–194 (1993)
O. Szász, Generalization of S. Bernstein’s polynomials to the infinite interval. J. Res. Nat. Bur. Stand. Sect. B 45, 239–245 (1950)
V. Totik, Uniform approximation by Szász–Mirakjan-type operators. Acta Math. Hung. 41(3–4), 291–307 (1983)
V. Totik, Uniform approximation by positive operators on infinite intervals. Anal. Math. 10(2), 163–182 (1984)
O.P. Varshney, S.R. Singh, On degree of approximation by positive linear operators. Rend. Mat. 2(7), 219–225 (1982)
Acknowledgements
Professor H. Gonska turned my attention to the fact that J. Favard also introduced and studied the approximation properties of a general class of operators, to which \(S_n\) belongs. I am also thankful to Kiril Delev who provided me with Favard’s paper [11].
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
This work was supported by Grant DN 02/14 of the Fund for Scientific Research of the Bulgarian Ministry of Education and Science.
Rights and permissions
About this article
Cite this article
Draganov, B.R. Direct estimates of the weighted simultaneous approximation by the Szász–Mirakjan operator. Period Math Hung 83, 88–109 (2021). https://doi.org/10.1007/s10998-020-00370-x
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10998-020-00370-x
Keywords
- Szász–Mirakjan operator
- Jackson inequality
- Direct estimate
- Simultaneous approximation
- Modulus of smoothness
- K-functional