Skip to main content
Log in

The Krzyż Conjecture and an Entropy Conjecture

  • Published:
Journal d'Analyse Mathématique Aims and scope

Abstract

We show that if the minimum entropy for a polynomial with roots on the unit circle is attained by polynomials with equally spaced roots, then, under a generic hypothesis about the nature of the extremum, the Krzyz conjecture on the maximum modulus of the Taylor coefficients of a holomorphic function that maps the disk to the punctured disk is true.

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. J. Agler and J. E. McCarthy, Pick Interpolation and Hilbert Function Spaces, American Mathematical Society, Providence, RI, 2002.

    Book  Google Scholar 

  2. A. Baernstein, Private communication, 2008.

  3. J. A. Ball, I. Gohberg and L. Rodman, Interpolation of Rational Matrix Functions, Birkhäuser, Basel, 1990.

    Book  Google Scholar 

  4. W. Beckner, Inequalities in Fourier analysis, Ann. of Math. (2) 102 (1975), 159–182.

    Article  MathSciNet  Google Scholar 

  5. J. E. Brown, Iteration of functions subordinate to schlicht functions, Complex Var. Theory Appl. 9 (1987), 143–152.

    MathSciNet  MATH  Google Scholar 

  6. R. J. P. M. Ermers, Coefficient Estimates for Bounded Non-Vanishing Functions, Ph.D. Tesis, Katholieke Universiteit Nijmegen, 1990.

    Google Scholar 

  7. C. Foiaş and A. E. Frazho, The Commutant Lifting Approach to Interpolation Problems, Birkhäuser, Basel, 1990.

    Book  Google Scholar 

  8. I. I. Hirschman Jr., A note on entropy, Amer. J. Math. 79 (1957), 152–156.

    Article  MathSciNet  Google Scholar 

  9. C. Horowitz, Coefficients of nonvanishing functions in H, Israel J. Math. 30 (1978), 285–291.

    Article  MathSciNet  Google Scholar 

  10. J. A. Hummel, S. Scheinberg and L. Zalcman, A coefficient problem for bounded non-vanishing functions, J. Anal. Math. 34 (1977), 169–190.

    Article  Google Scholar 

  11. J. Krzyż, Coefficient problem for bounded non-vanishing functions, Ann. Polon. Math. 20 (1969), 314.

    Google Scholar 

  12. M. J. Martin, E. T. Sawyer, I. Uriarte-Tuero and D. Vukotić, The Krzyż conjecture revisited, Adv. Math. 273 (2015), 716–745.

    Article  MathSciNet  Google Scholar 

  13. G. Pick, Über die Beschränkungen analytischer Funktionen, welche durch vorgegebene Funktionswerte bewirkt werden, Math. Ann. 77 (1916), 7–23.

    Article  Google Scholar 

  14. N. Samaris, A proof of Krzyż’s conjecture for the fifth coefficient, Complex Var. Theory Appl. 48 (2003), 753–766.

    MathSciNet  MATH  Google Scholar 

  15. D. L. Tan, Estimates of coefficients of bounded non-vanishing analytic functions, Chin. Ann. Math. Ser. A 4 (1983), 97–104.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to John E. McCarthy.

Additional information

Partially supported by National Science Foundation Grant DMS 1665260.

Partially supported by National Science Foundation Grant DMS 1565243.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Agler, J., McCarthy, J.E. The Krzyż Conjecture and an Entropy Conjecture. JAMA 144, 207–226 (2021). https://doi.org/10.1007/s11854-021-0178-z

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11854-021-0178-z

Navigation