Skip to main content
Log in

Direct and inverse results for multipoint Hermite–Padé approximants

  • Published:
Analysis and Mathematical Physics Aims and scope Submit manuscript

Abstract

Given a system of functions \({\mathbf {f}}=(f_1,\ldots ,f_d)\) analytic on a neighborhood of some compact subset E of the complex plane with simply connected complement in the extended complex plane, we give necessary and sufficient conditions for the convergence with geometric rate of the common denominators of row sequences of multipoint Hermite–Padé approximants under a general extremal condition on the table of interpolation points. The exact rate of convergence of these denominators is provided and the rate of convergence of the simultaneous approximants is estimated. These results allow us to detect the location of the poles of the system of functions which are in some sense closest to E.

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.

Institutional subscriptions

Similar content being viewed by others

References

  1. Bosuwan, N., López Lagomasino, G.: Determining system poles using row sequences of orthogonal Hermite–Padé approximants. J. Approx. Theory 231, 15–40 (2018)

    Article  MathSciNet  MATH  Google Scholar 

  2. Bosuwan, N., López Lagomasino, G.: Direct and inverse results on row sequences of simultaneous Padé–Faber approximants. Mediterr. J. Math. (accepted). arxiv:1801.03004

  3. Buslaev, V.I.: Relations for the coefficients, and singular points of a function. Math. USSR Sb. 59, 349–377 (1988)

    Article  MathSciNet  MATH  Google Scholar 

  4. Cacoq, J., de la Calle Ysern, B., López Lagomasino, G.: Incomplete Padé approximation and convergence of row sequences of Hermite–Padé approximants. J. Approx. Theory 170, 59–77 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  5. Cacoq, J., de la Calle Ysern, B., López Lagomasino, G.: Direct and inverse results on row sequences of Hermite–Padé approximants. Constr. Approx. 38, 133–160 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  6. Gonchar, A.A.: On convergence of Padé approximants for some classes of meromorphic functions. Math. USSR Sb. 26, 555–575 (1975)

    Article  MATH  Google Scholar 

  7. Gonchar, A.A.: Rational approximation of analytic functions. Proc. Steklov Inst. Math. 272, S44–S57 (2011)

    Article  MATH  Google Scholar 

  8. Gonchar, A.A.: Poles of rows of the Padé table and meromorphic continuation of functions. Sb. Math. 43, 527–546 (1982)

    Article  MATH  Google Scholar 

  9. Graves-Morris, P.R., Saff, E.B.: A de Montessus theorem for vector-valued rational interpolants. In: Graves-Morris, P.R., Saff, E.B., Varga, R.S. (eds.) Rational Approximation and Interpolation. Lecture Notes in Mathematics, vol. 1105, pp. 227–242. Springer, Berlin (1984)

    Chapter  Google Scholar 

  10. de Montessus de Ballore, R.: Sur les fractions continues algébriques. Bull. Soc. Math. Fr. 30, 28–36 (1902)

    Article  MATH  Google Scholar 

  11. Sidi, A.: A de Montessus type convergence study of a least-squares vector-valued rational interpolation procedure II. Comput. Methods Funct. Theory 10, 223–247 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  12. Van Barel, M., Bultheel, A.: A new approach to the rational interpolation problem: the vector case. J. Comput. Appl. Math. 33, 331–346 (1990)

    Article  MathSciNet  MATH  Google Scholar 

  13. Walsh, J.L.: Interpolation and Approximation by Rational Functions in the Complex Domain, vol. 20, 5th edn. Colloquium Publications, American Mathematical Society, Providence (1969)

    Google Scholar 

Download references

Acknowledgements

We wish to express our gratitude toward to an anonymous referee for careful reading, helpful comments, and suggestions leading to improvements of this work. The first author thanks Assoc. Prof. Chontita Rattanakul for her invaluable guidance.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to N. Bosuwan.

Ethics declarations

Conflict of interest

The authors declare to have no competing interests.

Additional information

Dedicated to Professor Stephen J. Gardiner on the occasion of his 60th birthday.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

The research of N. Bosuwan was supported by the Strengthen Research Grant for New Lecturer from the Thailand Research Fund and the Office of the Higher Education Commission (MRG6080133) and Faculty of Science, Mahidol University. The research of G. López Lagomasino and Y. Zaldivar Gerpe received support from Research Grant MTM 2015-65888-C4-2-P of Ministerio de Economía, Industria y Competitividad, Spain.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Bosuwan, N., López Lagomasino, G. & Zaldivar Gerpe, Y. Direct and inverse results for multipoint Hermite–Padé approximants. Anal.Math.Phys. 9, 761–779 (2019). https://doi.org/10.1007/s13324-019-00316-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13324-019-00316-8

Keywords

Mathematics Subject Classification

Navigation