Sharp Second-Order Hankel Determinants Bounds for Alpha-Convex Functions Connected with Modified Sigmoid Functions

The study of the Hankel determinant generated by the Maclaurin series of holomorphic functions belonging to particular classes of normalized univalent functions is one of the most significant problems in geometric function theory. Our goal in this study is first to define a family of alpha-convex fu...

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Main Authors: Muhammad Abbas, Reem K. Alhefthi, Daniele Ritelli, Muhammad Arif
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Axioms
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Online Access:https://www.mdpi.com/2075-1680/13/12/844
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author Muhammad Abbas
Reem K. Alhefthi
Daniele Ritelli
Muhammad Arif
author_facet Muhammad Abbas
Reem K. Alhefthi
Daniele Ritelli
Muhammad Arif
author_sort Muhammad Abbas
collection DOAJ
description The study of the Hankel determinant generated by the Maclaurin series of holomorphic functions belonging to particular classes of normalized univalent functions is one of the most significant problems in geometric function theory. Our goal in this study is first to define a family of alpha-convex functions associated with modified sigmoid functions and then to investigate sharp bounds of initial coefficients, Fekete-Szegö inequality, and second-order Hankel determinants. Moreover, we also examine the logarithmic and inverse coefficients of functions within a defined family regarding recent issues. All of the estimations that were found are sharp.
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institution Kabale University
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series Axioms
spelling doaj-art-f24114424f0d4e57adf9b2db04f39b582024-12-27T14:10:22ZengMDPI AGAxioms2075-16802024-12-01131284410.3390/axioms13120844Sharp Second-Order Hankel Determinants Bounds for Alpha-Convex Functions Connected with Modified Sigmoid FunctionsMuhammad Abbas0Reem K. Alhefthi1Daniele Ritelli2Muhammad Arif3Department of Mathematics, Abdul Wali Khan University Mardan, Mardan 23200, PakistanDepartment of Mathematics, College of Sciences, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi ArabiaDepartment of Statistical Sciences, Università di Bologna, 40126 Bologna, ItalyDepartment of Mathematics, Abdul Wali Khan University Mardan, Mardan 23200, PakistanThe study of the Hankel determinant generated by the Maclaurin series of holomorphic functions belonging to particular classes of normalized univalent functions is one of the most significant problems in geometric function theory. Our goal in this study is first to define a family of alpha-convex functions associated with modified sigmoid functions and then to investigate sharp bounds of initial coefficients, Fekete-Szegö inequality, and second-order Hankel determinants. Moreover, we also examine the logarithmic and inverse coefficients of functions within a defined family regarding recent issues. All of the estimations that were found are sharp.https://www.mdpi.com/2075-1680/13/12/844alpha-convex functionmodified sigmoid functionlogarithmic coefficientsinverse coefficientscoefficient boundsFekete-Szegö inequality
spellingShingle Muhammad Abbas
Reem K. Alhefthi
Daniele Ritelli
Muhammad Arif
Sharp Second-Order Hankel Determinants Bounds for Alpha-Convex Functions Connected with Modified Sigmoid Functions
Axioms
alpha-convex function
modified sigmoid function
logarithmic coefficients
inverse coefficients
coefficient bounds
Fekete-Szegö inequality
title Sharp Second-Order Hankel Determinants Bounds for Alpha-Convex Functions Connected with Modified Sigmoid Functions
title_full Sharp Second-Order Hankel Determinants Bounds for Alpha-Convex Functions Connected with Modified Sigmoid Functions
title_fullStr Sharp Second-Order Hankel Determinants Bounds for Alpha-Convex Functions Connected with Modified Sigmoid Functions
title_full_unstemmed Sharp Second-Order Hankel Determinants Bounds for Alpha-Convex Functions Connected with Modified Sigmoid Functions
title_short Sharp Second-Order Hankel Determinants Bounds for Alpha-Convex Functions Connected with Modified Sigmoid Functions
title_sort sharp second order hankel determinants bounds for alpha convex functions connected with modified sigmoid functions
topic alpha-convex function
modified sigmoid function
logarithmic coefficients
inverse coefficients
coefficient bounds
Fekete-Szegö inequality
url https://www.mdpi.com/2075-1680/13/12/844
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