Abstract

This note aims to highlight a general class of discrete linear and positive operators, focusing on some of their approximation properties. The construction includes a sequence of positive numbers ðknÞ, strictly decreasing. Imposing additional conditions on it, we set the convergence of the operators towards the identity operator and establish upper bounds for the error of approximation. A probabilistic approach is given. Also, in certain weighted spaces the study of its approximation properties is developed.

Authors

Octavian Agratini
Department of Mathematics, Babes-Bolyai University, Cluj-Napoca, Romania

Keywords

Abdulofizov generalization; Balazs-Szabados operator; Korovkin theorem; modulus of smoothness.

Paper coordinates

O. Agratini, On a class of Bernstein-type rational functions, Numerical Functional Analysis and Optimization, 41 (2020) no. 4, pp. 483-494, https://doi.org/10.1080/01630563.2019.1664566

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[1] Balazs, K. (1975). Approximation by Bernstein type rational functions. Acta Math. Acad. Sci. Hungar. 26(1–2):123–134. DOI: 10.1007/BF01895955.
[2] Balazs, C., Szabados, J. (1982). Approximation by Bernstein type rational functions. II. Acta Math. Acad. Sci. Hungar. 40(3–4):331–337. DOI: 10.1007/BF01903593.
[3] Totik, V. (1984). Saturation for Bernstein type rational functions. Acta Math. Hung. Hungar. 43(3–4):219–250. DOI: 10.1007/BF01958021.
[4] Vecchia, B. D. (1989). On some preservation and asymptotic relations of a rational operators. Facta Universitatis (Nis). 4:57–62.
[5] Abel, U., Della Vecchia, B. (2000). Asymptotic approximation by the operators of K. Balazs and Szabados. Acta Sci. Math. (Szeged). 66:137–145.
[6] Agratini, O. (2002). On approximation properties of Balazs-Szabados operators and their Kantorovich extension. Korean J. Comput. Appl. Math. 9(2):361–372.
[7] Dogru, O. (2006). On statistical approximation properties of Stancu type bivariate generalization of q-Balazs-Szabados operators. In: Octavian A., Petru, B., eds. Numerical Analysis and Approximation Theory. Cluj-Napoca: Casa Cartii de Stiinta, pp. 179–194. Paper presented at the Proceedings of the International Conference (NAAT 2006) held at Babes-Bolyai University, Cluj-Napoca, July 5–8, 2006.
[8] Gal, S. G. (2009). Approximation by Complex Bernstein and Convolution Type Operators, Series on Concrete and Applicable Mathematics, Vol. 8. Hackensack, NJ: World Scientific Publishing.
[9] Ispir, N., Yildiz Ozkan, E. (2013). Approximation properties of complex q-Balazs-Szabados operators in compact disks. J. Inequal. Appl. 2013:361. DOI: 10.1186/1029-242X-2013-361.
[10] Mahmudov, N. I. (2016). Approximation properties of the q-Balazs-Szabados complex operators in the case q 1: Comput. Meth. Funct. Theory Theory. 16(4):567–583. Issue DOI: 10.1007/s40315-015-0154-7.
[11] Abel, U., Agratini, O. (2016). On the variation detracting property of operators of Balazs and Szabados. Acta Math. Hungar. Hungar. 150(2):383–395. Issue DOI: 10.1007/s10474-016-0642-x.
[12] Abdulofizov, S. (1980). Approximation by rational functions of the type of generalized Bernstein polynomials on the semiaxis. Izv. Akad. Nauk Tadzhik. SSR, Otdel. Fiz.-Mat. Khim. i Geol. Nauk. 2(76):78–81. (in Russian, Tajiki summary).
[13] Abdulofizov, S., Videnskii, V. S. (1978). Approximation on a semi-axis by rational functions of Bernstein polynomial type. In: 31st Gertsen Lectures: Non-Linear Functional Analysis and the Theory of Approximation of Functions.  Leningrad: Leningrad, Gos. Ped. Inst, pp. 1–3 (in Russian).
[14] Lorentz, G. G. (1986). Bernstein Polynomials, 2nd ed. New York, NY: Chelsea Publ. Comp.
[15] DeVore, R. A., Lorentz, G. G. (1993). Constructive approximation. In: Grundlehren Der Mathematischen Wissenschaften. Berlin, Heidelberg: Springer-Verlag, pp. 303.
[16] Altomare, F., Campiti, M. (1994). Korovkin-Type Approximation Theory and Its Applications, Walter de Gruyter Studies in Mathematics, Vol. 17. Berlin: de Gruyter & Co.
[17] Shisha, O., Mond, B. (1968). The degree of convergence of sequences of linear positive operators. Proc. Natl. Acad. Sci. USA. 60(4):1196–1200. DOI: 10.1073/pnas.60.4.1196.
[18] Gadzhiev, A. D. (1976). Theorems of Korovkin type. Math. Notes 20(5):995–998. DOI: 10.1007/BF01146928.
[19] Lopez-Moreno, A.-J. (2004). Weighted simultaneous approximation with Baskakov type operators. Acta Mathematica Hungar. 104(1/2):143–151. DOI: 10.1023/B:AMHU.0000034368.81211.23.

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