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24 Results Found

  • Article
  • Open Access
6 Citations
3,479 Views
14 Pages

18 April 2020

The main purpose of this investigation is to use quantum calculus approach and obtain the Bohr radius for the class of q-starlike (q-convex) functions of order α . The Bohr radius is also determined for a generalized class of q-Janowski st...

  • Article
  • Open Access
8 Citations
2,999 Views
10 Pages

An Application of Sălăgean Operator Concerning Starlike Functions

  • Hatun Özlem Güney,
  • Georgia Irina Oros and
  • Shigeyoshi Owa

27 January 2022

As an application of the well-known Sălăgean differential operator, a new operator is introduced and, using this, a new class of functions Sn(α) is defined, which has the classes of starlike and convex functions of order α as sp...

  • Article
  • Open Access
2 Citations
1,745 Views
16 Pages

Some Properties for Subordinations of Analytic Functions

  • Hatun Özlem Güney,
  • Daniel Breaz and
  • Shigeyoshi Owa

28 January 2023

Let the class of functions of f(z) of the form f(z)=z+∑k=2∞akzk, which are denoted by A and called analytic functions in the open-unit disk. There are many interesting properties of the functions f(z) in the class A concerning the subordina...

  • Article
  • Open Access
1 Citations
1,188 Views
12 Pages

7 February 2024

Let A¯ be the new general class of functions f(z) of the form f(z)=z+∑k=1∞a1+k2z1+k2 that are analytic in the open unit disc U. In the present paper, for f(z)∈A¯, we consider classes S∗¯(α), C¯(&al...

  • Article
  • Open Access
4 Citations
2,104 Views
16 Pages

On a Class of Analytic Functions Related to Robertson’s Formula Involving Crescent Shaped Domain and Lemniscate of Bernoulli

  • Lech Gruszecki,
  • Adam Lecko,
  • Gangadharan Murugusundaramoorthy and
  • Srikandan Sivasubramanian

6 April 2023

In this paper, we introduce and study the class of analytic functions in the unit disc, which are derived from Robertson’s analytic formula for starlike functions with respect to a boundary point combined with a subordination involving lemnisca...

  • Article
  • Open Access
9 Citations
2,659 Views
9 Pages

Simple Sufficient Subordination Conditions for Close-to-Convexity

  • Ebrahim Analouei Adegani,
  • Teodor Bulboacă and
  • Ahmad Motamednezhad

7 March 2019

Using several applications of the theory of differential subordination we obtain sufficient conditions for usually normalized analytic functions to belong to certain subclasses of close-to-convex functions and close-to-convex functions of order &a...

  • Article
  • Open Access
2 Citations
1,587 Views
22 Pages

Starlikeness Associated with the Van Der Pol Numbers

  • Mohsan Raza,
  • Hari Mohan Srivastava,
  • Qin Xin,
  • Fairouz Tchier,
  • Sarfraz Nawaz Malik and
  • Muhammad Arif

10 May 2023

In this paper, we define a subclass of starlike functions associated with the Van der Pol numbers. For this class, we derive structural formula, radius of starlikeness of order α, strong starlikeness, and some inclusion results. We also study r...

  • Article
  • Open Access
16 Citations
2,289 Views
23 Pages

On Starlike Functions of Negative Order Defined by q-Fractional Derivative

  • Sadia Riaz,
  • Ubaid Ahmed Nisar,
  • Qin Xin,
  • Sarfraz Nawaz Malik and
  • Abdul Raheem

In this paper, two new classes of q-starlike functions in an open unit disc are defined and studied by using the q-fractional derivative. The class Sq*˜(α), α∈(−3,1], q∈(0,1) generalizes the class Sq* of q-starlike f...

  • Article
  • Open Access
115 Citations
4,800 Views
14 Pages

Some General Classes of q-Starlike Functions Associated with the Janowski Functions

  • Hari M. Srivastava,
  • Muhammad Tahir,
  • Bilal Khan,
  • Qazi Zahoor Ahmad and
  • Nazar Khan

23 February 2019

By making use of the concept of basic (or q-) calculus, various families of q-extensions of starlike functions of order α in the open unit disk U were introduced and studied from many different viewpoints and perspectives. In this p...

  • Article
  • Open Access
5 Citations
1,529 Views
12 Pages

Study on the Criteria for Starlikeness in Integral Operators Involving Bessel Functions

  • Georgia Irina Oros,
  • Gheorghe Oros and
  • Daniela Andrada Bardac-Vlada

26 October 2023

The study presented in this paper follows a line of research familiar for Geometric Function Theory, which consists in defining new integral operators and conducting studies for revealing certain geometric properties of those integral operators such...

  • Article
  • Open Access
4 Citations
2,580 Views
13 Pages

New Criteria for Meromorphic Starlikeness and Close-to-Convexity

  • Ali Ebadian,
  • Nak Eun Cho,
  • Ebrahim Analouei Adegani and
  • Sibel Yalçın

The main purpose of current paper is to obtain some new criteria for meromorphic strongly starlike functions of order α and strongly close-to-convexity of order α . Furthermore, the main results presented here are compared with...

  • Article
  • Open Access
5 Citations
2,262 Views
21 Pages

Starlike Functions Associated with Secant Hyperbolic Function

  • Khadija Bano,
  • Mohsan Raza,
  • Qin Xin,
  • Fairouz Tchier and
  • Sarfraz Nawaz Malik

16 March 2023

Motivated by the recent work on the symmetric domains, this article investigates certain features of symmetric domain which are caused by the secant hyperbolic functions. Geometric characteristics of analytic functions associated with secant hyperbol...

  • Article
  • Open Access
1 Citations
1,447 Views
13 Pages

New Criteria for Convex-Exponent Product of Log-Harmonic Functions

  • Rasoul Aghalary,
  • Ali Ebadian,
  • Nak Eun Cho and
  • Mehri Alizadeh

22 April 2023

In this study, we consider different types of convex-exponent products of elements of a certain class of log-harmonic mapping and then find sufficient conditions for them to be starlike log-harmonic functions. For instance, we show that, if f is a sp...

  • Article
  • Open Access
10 Citations
1,949 Views
19 Pages

4 June 2023

The potential for widespread applications of the geometric and mapping properties of functions of a complex variable has motivated this article. On the other hand, the basic or quantum (or q-) derivatives and the basic or quantum (or q-) integrals ar...

  • Article
  • Open Access
1,870 Views
12 Pages

Properties of Functions Formed Using the Sakaguchi and Gao-Zhou Concept

  • Jonathan Aaron Azlan Mosiun and
  • Suzeini Abdul Halim

27 February 2020

This paper introduces a new class related to close-to-convex functions denoted by K s k , N . This class is based on combining the concepts of starlike functions with respect to N-ply symmetry points of the order α , introduced by...

  • Article
  • Open Access
1,724 Views
16 Pages

Subordinations and Norm Estimates for Functions Associated with Ma-Minda Subclasses

  • Aaisha Farzana Habibullah,
  • Muthusamy Palani Jeyaraman and
  • Teodor Bulboacă

11 August 2022

For a function p analytic in the open unit disc and satisfying p(0)=1, we prove certain subordination implications of the first order differential subordination 1+zp′(z)≺1+Mz, which provides sufficient conditions for a function to belong...

  • Article
  • Open Access
1 Citations
1,675 Views
19 Pages

Fractional Differential Operator Based on Quantum Calculus and Bi-Close-to-Convex Functions

  • Zeya Jia,
  • Alina Alb Lupaş,
  • Haifa Bin Jebreen,
  • Georgia Irina Oros,
  • Teodor Bulboacă and
  • Qazi Zahoor Ahmad

29 June 2024

In this article, we first consider the fractional q-differential operator and the λ,q-fractional differintegral operator Dqλ:A→A. Using the λ,q-fractional differintegral operator, we define two new subclasses of analytic fun...

  • Article
  • Open Access
7 Citations
2,035 Views
17 Pages

The results contained in this paper are the result of a study regarding fractional calculus combined with the classical theory of differential subordination established for analytic complex valued functions. A new operator is introduced by applying t...

  • Article
  • Open Access
308 Views
17 Pages

2 November 2025

This study introduces a new integral operator Ip,μδ that extends the traditional Rafid operator to meromorphic p-valent functions. Using this operator, we define and investigate two new subclasses: Σp+δ,μ,α, consisting o...

  • Article
  • Open Access
16 Citations
2,189 Views
16 Pages

Applications of Symmetric Quantum Calculus to the Class of Harmonic Functions

  • Mohammad Faisal Khan,
  • Isra Al-Shbeil,
  • Najla Aloraini,
  • Nazar Khan and
  • Shahid Khan

18 October 2022

In the past few years, many scholars gave much attention to the use of q-calculus in geometric functions theory, and they defined new subclasses of analytic and harmonic functions. While using the symmetric q-calculus in geometric function theory, ve...