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In this article we determine the coefficient bounds for functions in certain subclasses of analytic functions defined by subordination which are related to the well-known classes of starlike and convex functions. The main results deal with…

Complex Variables · Mathematics 2017-04-27 Nirupam Ghosh , A. Vasudevarao

Let $\mathcal{A}$ be the set of all analytic functions $f$ defined in the open unit disk $\mathbb{D}$ and satisfying $f(0)=f'(0)-1=0$. In this paper, we consider the function $\varphi_{\scriptscriptstyle {Ne}}(z):=1+z-z^3/3$, which maps the…

Complex Variables · Mathematics 2020-09-08 Lateef Ahmad Wani , A. Swaminathan

The primary objective of this work is to obtain some sufficient conditions so that normalized Gauss hypergeometric function satisfies exponential starlikeness and convexity in the unit disk. Moreover, conditions on parameter of this…

Complex Variables · Mathematics 2025-03-21 Anish Kumar , Sourav Das

For $0\leq\alpha\leq 1,$ let $H_{\alpha}(x,y)$ be the convex weighted harmonic mean of $x$ and $y.$ We establish differential subordination implications of the form \begin{equation*} H_{\alpha}(p(z),p(z)\Theta(z)+zp'(z)\Phi(z))\prec…

Complex Variables · Mathematics 2022-03-23 S. Sivaprasad Kumar , Priyanka Goel

Functions with fixed initial coefficient have been widely studied. A new methodology is proposed in this paper by making appropriate modifications and improvements to the theory of second-order differential subordination. Several…

Complex Variables · Mathematics 2012-08-02 Rosihan M. Ali , Sumit Nagpal , V. Ravichandran

This paper aims to pursue some classes of normalized analytic functions $f$ with fixed second coefficient defined on open unit disk, such that ${(1+z)^2f(z)}/{z}$ and ${(1+z)f(z)}/{z}$ are functions having positive real part. The radius of…

Complex Variables · Mathematics 2022-03-17 Sushil Kumar , Swati Anand , Naveen Kumar Jain

In this paper, we obtain some application of first-order differential subordination, superordination and sandwich-type results involving operator for certain normalized $p$-valent analytic functions. Further, properties of $p$-valent…

Complex Variables · Mathematics 2018-11-09 V. S. Masih , A. Ebadian , Sh. Najafzadeh

This paper investigates the lemniscate starlikeness of analytic functions by deriving specific conditions on their power series coefficients. The study utilizes the Cauchy product of power series along with key inequalities involving the…

Complex Variables · Mathematics 2025-12-02 Saiful R Mondal , Ahmad K. Al Abdulaali

In the present investigation, we employ a new technique to find several first and second order differential subordination implications involving the following starlike class associated with a bean shaped domain: \begin{equation*}…

Complex Variables · Mathematics 2025-04-24 S. Sivaprasad Kumar , Pooja Yadav

For every $q\in(0,1)$ and $0\le \alpha<1$ we define a class of analytic functions, the so-called $q$-starlike functions of order $\alpha$, on the open unit disk. We study this class of functions and explore some inclusion properties with…

Complex Variables · Mathematics 2015-09-14 Sarita Agrawal , Swadesh K. Sahoo

In this paper, we introduce and explore a new class of starlike functions denoted by $\mathcal{S}^*_{\mathfrak{B}}$, defined as follows: $$\mathcal{S}^*_{\mathfrak{B}}=\{f\in \mathcal{A}:zf'(z)/f(z)\prec…

Complex Variables · Mathematics 2024-03-22 S. Sivaprasad Kumar , Pooja Yadav

The known Ozaki's condition says that $\mathfrak{Re}\left\{f^{(p)}(z)\right\}>0$ for $|z|<1$ implies that $f(z)=z^p+a_{p+1}z^{p+1}+\cdots$ is at most $p$-valent in $\mathbb D$. In this paper prove an extension of Ozaki's condition. Also, we…

Complex Variables · Mathematics 2026-05-19 Mamoru Nunokawa$ , Janusz Sokol

For $ -1 \leq B \leq 1$ and $A>B$, let $\mathcal{S}^*[A,B]$ denote the class of generalized Janowski starlike functions consisting of all normalized analytic functions $f$ defined by the subordination $z f'(z)/f(z) \prec (1+ A z)/(1+ B z)$…

Complex Variables · Mathematics 2017-03-13 V. Ravichandran , Shelly Verma

The conditions on $A$, $B$, $\beta$ and $\gamma$ are obtained for an analytic function $p$ defined on the open unit disc $\mathbb{D}$ and normalized by $p(0)=1$ to be subordinate to $(1+Az)/(1+Bz)$, $-1\leq B<A \leq 1$ when $p(z)+…

Complex Variables · Mathematics 2021-01-18 Kanika Sharma , Rasoul Aghalary , V. Ravichandran

Let $\mathcal{A}$ consists of analytic functions $f:\mathbb{D}\to\mathbb{C}$ satisfying $f(0)=f'(0)-1=0$. Let $\mathcal{S}^*_{Ne}$ be the recently introduced Ma-Minda type functions family associated with the $2$-cusped kidney-shaped {\it…

Complex Variables · Mathematics 2022-05-18 A. Swaminathan , Lateef Ahmad Wani

This paper studies analytic functions $f$ defined on the open unit disk of the complex plane for which $f/g$ and $(1+z)g/z$ are both functions with positive real part for some analytic function $g$. We determine radius constants of these…

Complex Variables · Mathematics 2020-01-22 Asha Sebastian , V. Ravichandran

We consider normalized analytic function $f$ on the open unit disk for which either $\operatorname{Re} f(z)/g(z)>0$, $|f(z) /g(z) - 1|<1$ or $\operatorname{Re} (1-z^2) f(z) /z>0$ for some analytic function $g$ with $\operatorname{Re}…

Complex Variables · Mathematics 2020-06-23 Kanika Khatter , See Keong Lee , V. Ravichandran

Let $h$ and $g$ be two analytic functions in the unit disc $\Delta$ that $g(0)=1$. Also let $\beta$ be a complex number with ${\rm Re}\{\beta\}>-1/2$. A function $f$ is said to be log--harmonic mapping if it has the following representation…

Complex Variables · Mathematics 2019-06-20 Rahim Kargar , Hesam Mahzoon

For given non-negative real numbers $\alpha_k$ with $ \sum_{k=1}^{m}\alpha_k =1$ and normalized analytic functions $f_k$, $k=1,\dotsc,m$, defined on the open unit disc, let the functions $F$ and $F_n$ be defined by $…

Complex Variables · Mathematics 2022-01-06 Somya Malik , Vaithiyanathan Ravichandran

The object of the present paper is to study certain properties and characteristics of the operator $Q_{p,\beta}^{\alpha}$defined on p-valent analytic function by using technique of differential subordination.We also obtained result…

Complex Variables · Mathematics 2017-08-02 Ashok Kumar Sahoo