English

Hankel and Toeplitz determinants of logarithmic coefficients of Inverse functions for certain classes of univalent functions

Complex Variables 2023-08-04 v1

Abstract

The Hankel and Toeplitz determinants H2,1(Ff1/2)H_{2,1}(F_{f^{-1}}/2) and T2,1(Ff1/2)T_{2,1}(F_{f^{-1}}/2) are defined as: \begin{align*} H_{2,1}(F_{f^{-1}}/2):= \begin{vmatrix} \Gamma_1 & \Gamma_2 \Gamma_2 & \Gamma_3 \end{vmatrix} \;\;\mbox{and} \;\; T_{2,1}(F_{f^{-1}}/2):= \begin{vmatrix} \Gamma_1 & \Gamma_2 \Gamma_2 & \Gamma_1 \end{vmatrix} \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)1/4|H_{2,1}(F_{f^{-1}}/2)|\leq 1/4, H2,1(Ff1/2)1/36|H_{2,1}(F_{f^{-1}}/2)| \leq 1/36, T2,1(Ff1/2)5/16|T_{2,1}(F_{f^{-1}}/2)|\leq 5/16 and T2,1(Ff1/2)145/2304|T_{2,1}(F_{f^{-1}}/2)|\leq 145/2304 for the logarithmic coefficients of inverse functions for the classes starlike functions and convex functions with respect to symmetric points. In addition, our findings are substantiated further through the incorporation of illustrative examples, which support the strict inequality and lend credence to our conclusions.

Keywords

Cite

@article{arxiv.2308.01548,
  title  = {Hankel and Toeplitz determinants of logarithmic coefficients of Inverse functions for certain classes of univalent functions},
  author = {Sanju Mandal and Partha Pratim Roy and Molla Basir Ahamed},
  journal= {arXiv preprint arXiv:2308.01548},
  year   = {2023}
}

Comments

15 pages. arXiv admin note: substantial text overlap with arXiv:2305.12500, arXiv:2307.14365