Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 17 of 17

Full-Text Articles in Physical Sciences and Mathematics

Coefficient Bounds And Fekete-Szegӧ Problem For A New Subclasses Of Holomorphic Bi-Univalent Functions Defined By Horadam Polynomials, Najah Ali Jiben Al-Zaidi, Abbas Kareem Wanas Apr 2021

Coefficient Bounds And Fekete-Szegӧ Problem For A New Subclasses Of Holomorphic Bi-Univalent Functions Defined By Horadam Polynomials, Najah Ali Jiben Al-Zaidi, Abbas Kareem Wanas

Al-Qadisiyah Journal of Pure Science

In the present paper, by making use the Horadam polynomials, we introduce and investigate two new subclasses and of the function class of holomorphic bi-univalent functions in the open unit disk Δ. For functions belonging to this subclasses, we obtain upper bounds for the second and third coefficients and discuss Fekete-Szegӧ problem. Furthermore, we point out several new special cases of our results.


Faber Polynomial Coefficients For Certain Subclasses Of Analytic And Biunivalent Functions, Abdel Moneim Lashin, Fatma Elemam Jan 2020

Faber Polynomial Coefficients For Certain Subclasses Of Analytic And Biunivalent Functions, Abdel Moneim Lashin, Fatma Elemam

Turkish Journal of Mathematics

In this paper, we introduce and investigate two new subclasses of analytic and bi-univalent functions defined in the open unit disc. We use the Faber polynomial expansions to find upper bounds for the $n$th$~(n\geq 3)$ Taylor-Maclaurin coefficients $\left\vert a_{n}\right\vert $ of functions belong to these new subclasses with $a_{k}=0$ for $2\leq k\leq n-1$, also we find non-sharp estimates on the first two coefficients $\left\vert a_{2}\right\vert $ and $\left\vert a_{3}\right\vert $. The results, which are presented in this paper, would generalize those in related earlier works of several authors.


General Coefficient Estimates For Bi-Univalent Functions: A New Approach, Oqlah Alrefai, Mohammed Ali Jan 2020

General Coefficient Estimates For Bi-Univalent Functions: A New Approach, Oqlah Alrefai, Mohammed Ali

Turkish Journal of Mathematics

We prove for univalent functions $f(z)=z+\sum_{k=n}^{\infty}a_k z^k;(n\geq 2)$ in the unit disk $\mathbb{U}=\{z:\; z


Bounds For A New Subclass Of Bi-Univalent Functions Subordinate To The Fibonacci Numbers, Şahsene Altinkaya Jan 2020

Bounds For A New Subclass Of Bi-Univalent Functions Subordinate To The Fibonacci Numbers, Şahsene Altinkaya

Turkish Journal of Mathematics

In this investigation, by using a relation of subordination, we define a new subclass of analytic bi-univalent functions associated with the Fibonacci numbers. Moreover, we survey the bounds of the coefficients for functions in this class.


A New Comprehensive Subclass Of Analytic Bi-Close-To-Convex Functions, Serap Bulut Jan 2019

A New Comprehensive Subclass Of Analytic Bi-Close-To-Convex Functions, Serap Bulut

Turkish Journal of Mathematics

In a very recent work, Şeker and Sümer Eker [On subclasses of bi-close-to-convex functions related to the odd-starlike functions. Palestine Journal of Mathematics 2017; 6: 215-221] defined two subclasses of analytic bi-close-to-convex functions related to the odd-starlike functions in the open unit disk $\mathbb{U}$. The main purpose of this paper is to generalize and improve the results of Şeker and Sümer Eker (in the aforementioned study) defining a comprehensive subclass of bi-close-to-convex functions. Also, we investigate the Fekete-Szegö type coefficient bounds for functions belonging to this new class.


Inequalities On Coefficients For Certain Classes Of M-Fold Symmetric And Bi-Univalent Functions Equipped With Faber Polynomial, Fethi̇ye Müge Sakar, Adnan Canbulat Jan 2019

Inequalities On Coefficients For Certain Classes Of M-Fold Symmetric And Bi-Univalent Functions Equipped With Faber Polynomial, Fethi̇ye Müge Sakar, Adnan Canbulat

Turkish Journal of Mathematics

In this work, considering a new subclass of bi-univalent functions which are m-fold symmetric and analytic functions in the open unit disk, we determine estimates for the general Taylor-Maclaurin coefficient of the functions in this class. Furthermore, initial upper bounds of coefficients for m-fold symmetric, analytic and bi-univalent functions were found in this study. For this purpose, we used the Faber polynomial expansions. In certain cases, the coefficient bounds presented in this paper would generalize and improve some recent works in the literature. We hope that this paper will inspire future researchers in applying our approach to other related problems.


Inclusion Properties Of Lucas Polynomials For Bi-Univalent Functionsintroduced Through The $\Mathfrak{Q}$-Analogue Of The Noor Integral Operator, Şahsene Altinkaya Jan 2019

Inclusion Properties Of Lucas Polynomials For Bi-Univalent Functionsintroduced Through The $\Mathfrak{Q}$-Analogue Of The Noor Integral Operator, Şahsene Altinkaya

Turkish Journal of Mathematics

In this paper, by using the $(\mathbf{P},\mathbf{Q})$-Lucas polynomials and the $\mathfrak{q}$-analogue of the Noor integral operator, we aim to build a bridge between the theory of geometric functions and that of special functions.


A New General Subclass Of Analytic Bi-Univalent Functions, Serap Bulut Jan 2019

A New General Subclass Of Analytic Bi-Univalent Functions, Serap Bulut

Turkish Journal of Mathematics

In a very recent work, Şeker [Seker B. On a new subclass of bi-univalent functions defined by using Salagean operator. Turkish Journal of Mathematics 2018; 42: 2891-2896] defined two subclasses of analytic bi-univalent functions by means of Salagean differential operator and he obtained the initial Taylor-Maclaurin coefficient estimates for functions belonging to these classes. The main purpose of this paper is to improve the results obtained by Şeker in the aforementioned study. For this purpose, we define a general subclass of bi-univalent functions.


$(P,Q)$-Lucas Polynomial Coefficient Inequalities Of Thebi-Univalent Function Class, Arzu Akgül Jan 2019

$(P,Q)$-Lucas Polynomial Coefficient Inequalities Of Thebi-Univalent Function Class, Arzu Akgül

Turkish Journal of Mathematics

Recently, Lucas polynomials and other special polynomials gained importance in the field of geometric function theory. In this study, by connecting these polynomials, subordination, and the Al-Oboudi differential operator, we introduce a new class of bi-univalent functions and obtain coefficient estimates and Fekete-SzegÖ inequalities for this new class.


A Certain Subclass Of Bi-Univalent Analytic Functions Introduced Bymeans Of The $Q$-Analogue Of Noor Integral Operator And Horadam Polynomials, Arzu Akgül, Fethi̇ye Müge Sakar Jan 2019

A Certain Subclass Of Bi-Univalent Analytic Functions Introduced Bymeans Of The $Q$-Analogue Of Noor Integral Operator And Horadam Polynomials, Arzu Akgül, Fethi̇ye Müge Sakar

Turkish Journal of Mathematics

In the present study, by using the Horadam Polnomials and $q-$analogue of Noor integral oprerator, we target to construct an interesting connection between the geometric function theory and that of special functions. Also, by defining a new class of bi-univalent analytic functions, we investigate coefficient estimates and famous Fekete-Szegö inequality for functions belonging to this interesting class.


Second Hankel Determinant For A Subclass Of Analytic Bi-Univalent Functions Defined By Subordination, Ahmad Motamednezhad, Teodor Bulboaca, Ebrahim Analouei Adegani, Nesa Dibagar Jan 2018

Second Hankel Determinant For A Subclass Of Analytic Bi-Univalent Functions Defined By Subordination, Ahmad Motamednezhad, Teodor Bulboaca, Ebrahim Analouei Adegani, Nesa Dibagar

Turkish Journal of Mathematics

In this work with a different technique we obtain upper bounds of the functional $\left a_2a_4-a_3^2\right $ for functions belonging to a comprehensive subclass of analytic bi-univalent functions, which is defined by subordinations in the open unit disk. Moreover, our results extend and improve some of the previously known ones.


On A New Subclass Of Bi-Univalent Functions Defined By Using Salagean Operator, Bi̇lal Şeker Jan 2018

On A New Subclass Of Bi-Univalent Functions Defined By Using Salagean Operator, Bi̇lal Şeker

Turkish Journal of Mathematics

In this manuscript, by using the Salagean operator, new subclasses of bi-univalent functions in the open unit disk are defined. Moreover, for functions belonging to these new subclasses, upper bounds for the second and third coefficients are found.


Second Hankel Determinant For Certain Subclasses Ofbi-Univalent Functions, Murat Çağlar, Erhan Deni̇z, Hari Mohan Srivastava Jan 2017

Second Hankel Determinant For Certain Subclasses Ofbi-Univalent Functions, Murat Çağlar, Erhan Deni̇z, Hari Mohan Srivastava

Turkish Journal of Mathematics

In the present paper, we obtain the upper bounds for the second Hankel determinant for certain subclasses of analytic and bi-univalent functions. Moreover, several interesting applications of the results presented here are also discussed.


Coefficient Bounds For A New Subclass Of Analytic Bi-Close-To-Convex Functions By Making Use Of Faber Polynomial Expansion, Fethi̇ye Müge Sakar, Hatun Özlem Güney Jan 2017

Coefficient Bounds For A New Subclass Of Analytic Bi-Close-To-Convex Functions By Making Use Of Faber Polynomial Expansion, Fethi̇ye Müge Sakar, Hatun Özlem Güney

Turkish Journal of Mathematics

Recently, in the literature, we can see quite a few papers about general coefficient bounds for subclasses of bi-univalent functions. However, we can find just a few papers about general coefficient estimates for subclasses of bi-close-to-convex functions. In the present study, we give and look into a new subclass of analytic and bi-close-to-convex functions in the open unit disk. Making use of the Faber series, we have an upper bound for the general coefficient of functions in this class. We also demonstrate the invisible behavior of the beginning coefficients of a special subclass of bi-close-to-convex functions.


Coefficient Estimates For General Subclasses Of $M$-Foldsymmetric Analytic Bi-Univalent Functions, Serap Bulut Jan 2016

Coefficient Estimates For General Subclasses Of $M$-Foldsymmetric Analytic Bi-Univalent Functions, Serap Bulut

Turkish Journal of Mathematics

In this work, we introduce and investigate two new subclasses of the bi-univalent functions in which both $f$ and $f^{-1}$ are $ m$-fold symmetric analytic functions. For functions in each of the subclasses introduced in this paper, we obtain the coefficient bounds for $ \left\vert a_{m+1}\right\vert $ and $\left\vert a_{2m+1}\right\vert .$


Coefficient Bounds For Subclasses Of M-Fold Symmetric Bi-Univalent Functions, Sevtap Sümer Eker Jan 2016

Coefficient Bounds For Subclasses Of M-Fold Symmetric Bi-Univalent Functions, Sevtap Sümer Eker

Turkish Journal of Mathematics

In this study, we introduce and investigate two new subclasses of the bi-univalent functions; both $f(z)$ and $f^{-1}(z)$ are m-fold symmetric analytic functions. Among other results, upper bounds for the coefficients $\left a_{m+1}\right $ and $\left a_{2m+1}\right $ are found in this investigation.


Bounds For The Second Hankel Determinant Of Certain Bi-Univalent Functions, Hali̇t Orhan, Nanjundan Magesh, Jagadeesan Yamini Jan 2016

Bounds For The Second Hankel Determinant Of Certain Bi-Univalent Functions, Hali̇t Orhan, Nanjundan Magesh, Jagadeesan Yamini

Turkish Journal of Mathematics

We investigate the second Hankel determinant inequalities for a certain class of analytic and bi-univalent functions. Some interesting applications of the results presented here are also discussed.