Abstract
For meromorphic circumferentially mean p-valent functions, an analog of the classical distortion theorem is proved. It is shown that the existence of connected lemniscates of the function and a constraint on a cover of two given points lead to an inequality involving the Green energy of a discrete signedmeasure concentrated at the zeros of the given function and the absolute values of its derivatives at these zeros. This inequality is an equality for the superposition of a certain univalent function and an appropriate Zolotarev fraction.
Similar content being viewed by others
References
V. N. Dubinin, “Lemniscate zone and distortion theorems for multivalent functions,” Zap. Nauchn. Sem. POMI 458, 17–30 (2017) [J.Math. Sci. 234 (5), 598–607 (2018)].
C. Carathéodory, “Sur quelques applications du théorè me de Landau–Picard,” Compt. Rend. Acad. Sci. 144, 1203–1206 (1907).
G. M. Goluzin, The Geometric Theory of Functions of a Complex Variable (Nauka, Moscow, 1966) [in Russian].
M. Biernacki, “Sur les fonctions en moyenne multivalentes,” Bull. Sci. Math. (2) 70, 51–76 (1946).
W. K. Hayman, Multivalent Functions, in Cambridge Tracts in Math. (Cambridge Univ. Press, Cambridge, 1994), Vol.100.
J. A. Jenkins, Univalent Functions and Conformal Mapping (Springer-Verlag, Berlin–Heidelberg, 1958; Inostrannaya Literatura, Moscow, 1962).
V. N. Dubinin, “Circular symmetrization of condensers on Riemann surfaces,” Mat. Sb. 206 (1), 69–96 (2015) [Sb.Math. 206 (1), 61–86 (2015)].
V. N. Dubinin, “A new version of circular symmetrization with applications to p-valent functions,” Mat. Sb. 203 (7), 79–94 (2012) [Sb.Math. 203 (7), 996–1011 (2012)].
V. N. Dubinin, “Symmetrization of condensers and inequalities for functions multivalent in a disk,” Mat. Zametki 94 (6), 846–856 (2013) [Math. Notes 94 (6), 876–884 (2013)].
V. N. Dubinin, “Distortion theorems for circumferentially mean p-valent functions,” Zap. Nauchn. Sem. POMI 440, 43–56 (2015) [J.Math. Sci. 217 (1), 28–36 (2016)].
N. S. Landkof, Foundations of Modern Potential Theory (Nauka, Moscow, 1966; Springer-Verlag, Berlin–Heidelberg, 1972). [in Russian].
V. N. Dubinin, “The logarithmic energy of zeros and poles of a rational function,” Sibirsk. Mat. Zh. 57 (6), 1255–1261 (2016) [SiberianMath. J. 57 (6), 981–986 (2016)].
V. N. Dubinin, “An extremal problem for the derivative of a rational function,” Mat. Zametki 100 (5), 732–738 (2016) [Math. Notes 100 (5), 714–719 (2016)].
N. I. Akhiezer, Elements of the Theory of Elliptic Functions (Nauka, Moscow, 1970; Amer. Math. Soc., Providence, RI, 1990).
V. N. Dubinin, “Inequalities for themoduli of circumferentially mean p-valent functions,” Zap. Nauchn. Sem. POMI 429, 44–54 (2014) [J. Math. Sci. 207 (6), 832–838 (2015)].
V. N. Dubinin, Condenser Capacities and Symmetrization in Geometric Function Theory (Birkhäuser, Basel, 2014).
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © V. N. Dubinin, 2018, published in Matematicheskie Zametki, 2018, Vol. 104, No. 5, pp. 700–707.
Rights and permissions
About this article
Cite this article
Dubinin, V.N. Lemniscate Zone and Distortion Theorems for Multivalent Functions. II. Math Notes 104, 683–688 (2018). https://doi.org/10.1134/S0001434618110081
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0001434618110081