Some application of Grunsky coefficients in the theory of univalent functions
Abstract Let function f be normalized, analytic and univalent in the unit disk 𝔻 = { z : | z | < 1} and <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mrow> <m:mi>f</m:mi> <m:mrow> <m:mo>(</m:mo> <m:mi>z</m:mi> <m:mo>)</m:mo> </m:mrow> <m:mo>=</m:mo> <m:mi>z</m:mi> <m:mo>+</m:mo> <m:msubsup> <m:mo>∑</m:mo> <m:mrow> <m:mi>n</m:mi> <m:mo>=</m:mo> <m:mn>2</m:mn> </m:mrow> <m:mo>∞</m:mo> </m:msubsup> <m:mrow> <m:msub> <m:mrow> <m:mi>a</m:mi> </m:mrow> <m:mi>n</m:mi> </m:msub> <m:msup> <m:mrow> <m:mi>z</m:mi> </m:mrow> <m:mi>n</m:mi> </m:msup> </m:mrow> </m:mrow> </m:math> f\left( z \right) = z + \sum\nolimits_{n = 2}^\infty {{a_n}{z^n}} . Using a method based on Grusky coefficients we study several problems over that class of univalent functions: upper bounds of the special case of the generalized Zalcman conjecture | a 2 a 3 − a 4 |, of the third logarithmic coefficient, and of the second Hankel determinant for the logarithmic coefficients.
Authors
- Milutin Obradović (ORCID: https://orcid.org/0000-0001-8890-0764)
- Nikola Tuneski (ORCID: https://orcid.org/0000-0003-3889-0048)
Institutions
- University of Belgrade (RS)
- Ss. Cyril and Methodius University in Skopje (MK)
Publication Details
- Journal
- Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica
- Published
- 2025-11-26
- DOI
- https://doi.org/10.2478/aupcsm-2025-0005
- Primary Topic
- Analytic and geometric function theory
- Type
- article
- Field-Weighted Citation Impact
- 0.00