English

Second Hankel determinant of logarithmic coefficients of inverse functions in certain classes of univalent functions

Complex Variables 2023-07-28 v1

Abstract

The Hankel determinant H2,1(Ff1/2)H_{2,1}(F_{f^{-1}}/2) of logarithmic coefficients is defined as: \begin{align*} H_{2,1}(F_{f^{-1}}/2):= \begin{vmatrix} \Gamma_1 & \Gamma_2 \Gamma_2 & \Gamma_3 \end{vmatrix}=\Gamma_1\Gamma_3-\Gamma^2_2, \end{align*} where Γ1,Γ2,\Gamma_1, \Gamma_2, and Γ3\Gamma_3 are the first, second and third logarithmic coefficients of inverse functions belonging to the class S\mathcal{S} of normalized univalent functions. In this article, we establish sharp inequalities H2,1(Ff1/2)19/288|H_{2,1}(F_{f^{-1}}/2)|\leq 19/288, H2,1(Ff1/2)1/144|H_{2,1}(F_{f^{-1}}/2)| \leq 1/144, and H2,1(Ff1/2)1/36|H_{2,1}(F_{f^{-1}}/2)| \leq 1/36 for the logarithmic coefficients of inverse functions, considering starlike and convex functions, as well as functions with bounded turning of order 1/21/2, respectively.

Keywords

Cite

@article{arxiv.2307.14365,
  title  = {Second Hankel determinant of logarithmic coefficients of inverse functions in certain classes of univalent functions},
  author = {Sanju Mandal and Molla Basir Ahamed},
  journal= {arXiv preprint arXiv:2307.14365},
  year   = {2023}
}

Comments

14. arXiv admin note: substantial text overlap with arXiv:2307.02741