Skip to main content
Log in

Uniform convergence of the p-Bieberbach polynomials in domains with zero angles

  • Articles
  • Published:
Science China Mathematics Aims and scope Submit manuscript

Abstract

Let G ⊂ ℂ be a simply connected domain whose boundary L := ∂G is a Jordan curve and 0 ∈ G. Let w = φ(z) be the conformal mapping of G onto the disk B(0, r 0) := {w : |w| < r 0}, satisfying φ(0) = 0, φ′(0) = 1. We consider the following extremal problem for p > 0:

$\iint_G {|\phi '(z) - P'_n (z)|^p d\sigma _z \to \min }$

in the class of all polynomials P n (z) of degree not exceeding n with P n (0) = 0, P n ′ (0) = 1. The solution to this extremal problem is called the p-Bieberbach polynomial of degree n for the pair (G, 0). We study the uniform convergence of the p-Bieberbach polynomials B n,p (z) to the φ(z) on \(\bar G\) with interior and exterior zero angles determined depending on the properties of boundary arcs and the degree of their “touch”.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Abdullayev F G. On the Orthogonal Polynomials in Domains with Quasiconformal Boundary (in Russian). Donetsk: Dissertation, 1986

    Google Scholar 

  2. Abdullayev F G. On the convergence of Bieberbach polynomials in domains with interior zero angles (in Russian). Dokl Akad Nauk Ukrain SSR Ser A, 1989, 12:3–5

    Google Scholar 

  3. Abdullayev F G. On the convergence of Fourier series by orthogonal polynomials in domains with piecewisequasiconformal boundary. In: Theory of Mapping and Approx. Kiev: Naukova Dumka, 1989, 3–12

    Google Scholar 

  4. Abdullayev F G. Uniform convergence of the generalized Bieberbach polynomials in regions with non zero angles. Acta Math Hung, 1997, 77:223–246

    Article  MATH  MathSciNet  Google Scholar 

  5. Abdullayev F G. Uniform convergence of generalized Bieberbach polynomials in regions with zero angles. Czechoslovak Math J, 2001, 51:643–660

    Article  MATH  MathSciNet  Google Scholar 

  6. Abdullayev F G. Uniform convergence of the Bieberbach polynomials inside and on the closure of domain in the complex plane. East J Approx, 2001, 7:77–101

    MATH  MathSciNet  Google Scholar 

  7. Abdullayev F G, Küçükaslan M. New extremal polynomials and its approximations properties. Novisad J Math, 2009, 39:1–12

    Google Scholar 

  8. Ahlfors L V. Lectures on Quasiconformal Mappings. Princeton, NJ: Van Nostrand, 1966

    MATH  Google Scholar 

  9. Andrievskii V V. Uniform convergence of Bieberbach polynomials in domains with piecewise quasiconformal boundary (in Russian). In: Theory of Mappings and Approximation of Functions. Kiev: Naukova Dumka, 1983, 3–18

    Google Scholar 

  10. Andrievskii V V, Belyi V I, Dzjadyk V K. Conformal Invariants in Constructive Theory of Functions of Complex Variable. Atlanta: World Federation Pub, 1995

    MATH  Google Scholar 

  11. Andrievskii V V, Gaier D. Uniform convergence of Bieberbach polynomials in domains with piecewise quasianalytic boundary. Mitteilungen aus dem Mathematischen Seminar Giessen, 1992, 211:49–60

    MathSciNet  Google Scholar 

  12. Belyi V I. Conformal mappings and the approximation of analytic functions in domains with a quasiconformal boundary. Math USSR-Sb, 1977, 31:289–317

    Article  MATH  Google Scholar 

  13. Davis P J. Interpolation and Approximation. New York: Blaisdell Publishing Company, 1963

    MATH  Google Scholar 

  14. Gaier D. On the convergence of the Bieberbach polynomials in regions with corners. Constructive Approx, 1988, 4:289–305

    Article  MATH  MathSciNet  Google Scholar 

  15. Israfilov D M. Uniform convergence of the Bieberbach polynomials in closed smooth domains of bounded boundary rotation. J Approx Theory, 2003, 125:116–130

    Article  MATH  MathSciNet  Google Scholar 

  16. Keldych M V. Sur l’approximation en moyenne quadratique des fonctions analytiques. Math Sb, 1939, 5:391–401

    MATH  MathSciNet  Google Scholar 

  17. Koşar C, Kucukaslan M, Abdullayev F G. Uniform convergence of extremal polynomıals when domaıns with corners and specıal cusps on the boundary. Adv Pure Math, 2011, 1:305–314

    Article  MATH  Google Scholar 

  18. Küçükaslan M, Koşar C, Abdullayev F G. Uniform convergence of some extremal polynomials in domain with corners on the boundary. J Inequal Appl, doi:10.1155/2010/716176, 2010

    Google Scholar 

  19. Lehto O, Virtanen K I. Quasiconformal Mappings in the Plane. Berlin: Springer-Verlag, 1973

    Book  MATH  Google Scholar 

  20. Mergelyan S N. Certain questions of the constructive theory of functions (in Russian). Trudy Math Inst Steklov, 1951, 37:3–91

    MathSciNet  Google Scholar 

  21. Privalov I I. Introduction to the Theory of Functions of a Complex Variable. Moscow: Nauka, 1984

    MATH  Google Scholar 

  22. Rickman S. Characterization of quasiconformal arcs. Annal Acad Sci Fenn Ser A I Math, 1996, 395:1–30

    Google Scholar 

  23. Simonenko I B. On the convergence of Bieberbach polynomials in the case of a Lipschitz domain. Math USSR-Izv, 1980, 13:166–174

    Article  Google Scholar 

  24. Smirnov V I, Lebedev N A. Functions of a Complex Variable: Constructive Theory. Cambridge: MIT Press, 1968

    MATH  Google Scholar 

  25. Suetin P K. Polynomials Orthogonal over the Region and Bieberbach Polynomial. Providence, RI: Amer Math Soc, 1974

    Google Scholar 

  26. Tamrazov P M. Smoothness and Polynomial Approx (in Russian). Kiev: Naukova Dumka, 1975

    Google Scholar 

  27. Walsh J L. Interpolation and Approximation by Rational Functions in the Complex Domain (in Russian). Providence, RI: Amer Math Soc, 1961

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Fahreddin G. Abdullayev.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Abdullayev, F.G., Özkartepe, P.N. Uniform convergence of the p-Bieberbach polynomials in domains with zero angles. Sci. China Math. 58, 1063–1078 (2015). https://doi.org/10.1007/s11425-014-4908-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11425-014-4908-x

Keywords

MSC(2010)

Navigation