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.
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J. Agler and J. E. McCarthy, Pick Interpolation and Hilbert Function Spaces, American Mathematical Society, Providence, RI, 2002.
A. Baernstein, Private communication, 2008.
J. A. Ball, I. Gohberg and L. Rodman, Interpolation of Rational Matrix Functions, Birkhäuser, Basel, 1990.
W. Beckner, Inequalities in Fourier analysis, Ann. of Math. (2) 102 (1975), 159–182.
J. E. Brown, Iteration of functions subordinate to schlicht functions, Complex Var. Theory Appl. 9 (1987), 143–152.
R. J. P. M. Ermers, Coefficient Estimates for Bounded Non-Vanishing Functions, Ph.D. Tesis, Katholieke Universiteit Nijmegen, 1990.
C. Foiaş and A. E. Frazho, The Commutant Lifting Approach to Interpolation Problems, Birkhäuser, Basel, 1990.
I. I. Hirschman Jr., A note on entropy, Amer. J. Math. 79 (1957), 152–156.
C. Horowitz, Coefficients of nonvanishing functions in H∞, Israel J. Math. 30 (1978), 285–291.
J. A. Hummel, S. Scheinberg and L. Zalcman, A coefficient problem for bounded non-vanishing functions, J. Anal. Math. 34 (1977), 169–190.
J. Krzyż, Coefficient problem for bounded non-vanishing functions, Ann. Polon. Math. 20 (1969), 314.
M. J. Martin, E. T. Sawyer, I. Uriarte-Tuero and D. Vukotić, The Krzyż conjecture revisited, Adv. Math. 273 (2015), 716–745.
G. Pick, Über die Beschränkungen analytischer Funktionen, welche durch vorgegebene Funktionswerte bewirkt werden, Math. Ann. 77 (1916), 7–23.
N. Samaris, A proof of Krzyż’s conjecture for the fifth coefficient, Complex Var. Theory Appl. 48 (2003), 753–766.
D. L. Tan, Estimates of coefficients of bounded non-vanishing analytic functions, Chin. Ann. Math. Ser. A 4 (1983), 97–104.
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Partially supported by National Science Foundation Grant DMS 1665260.
Partially supported by National Science Foundation Grant DMS 1565243.
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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
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DOI: https://doi.org/10.1007/s11854-021-0178-z