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Related papers: On analytic functions related to Booth-lemniscate

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There are a number of articles which deal with Bohr's phenomenon whereas only a few papers appeared in the literature on Rogosinski's radii for analytic functions defined on the unit disk $|z|<1$. In this article, we introduce and…

Complex Variables · Mathematics 2017-08-21 Ilgiz R Kayumov , Saminathan Ponnusamy

In this paper, we establish the sharp estimates of the pre-Schwarzian norm of functions $f$ in the Ma-Minda type starlike and convex classes $\mathcal{S}^*(\varphi)$ and $\mathcal{C}(\varphi)$, respectively, whenever…

Complex Variables · Mathematics 2025-05-06 Raju Biswas

For $\alpha > -1$ and $\beta >0, $ let $\mathcal{B}_{\mathcal{H}}^0(\alpha, \beta)$ denote the class of sense preserving harmonic mappings $f=h+\overline{g}$ in the open unit disk $\mathbb{D}$ satisfying $|zh''(z)+\alpha(h'(z)-1)|\leq…

Complex Variables · Mathematics 2021-03-19 Manivannan Mathi , Jugal Kishore Prajapat

For $\lambda\ge0$, the so-called $\lambda$-analytic functions are defined in terms of the (complex) Dunkl operators $D_{z}$ and $D_{\bar{z}}$. In the paper we introduce a Bloch type space on the disk ${\mathbb D}$ associated with…

Complex Variables · Mathematics 2026-03-27 Haihua Wei , Kanghui Qian , Zhongkai Li , Yeli Niu

A holomorphic function $f$ on the unit disc $\mathbb{D}$ belongs to the class $\mathcal{U}_A(\mathbb{D})$ of Abel universal functions if the family $\{f_r: 0\leq r<1\}$ of its dilates $f_r(z):=f(rz)$ is dense in the space of continuous…

Complex Variables · Mathematics 2023-10-10 Stéphane Charpentier , Myrto Manolaki , Konstantinos Maronikolakis

We introduce a class of analytic functions subordinate to the function $1+\sinh \left( z\right) $ and obtain various necessary and sufficient conditions for functions to be in the class. These conditions mainly comprise of the coefficient…

Complex Variables · Mathematics 2020-11-11 S. Sivaprasad Kumar , Muhammad Ghaffar Khan , Bakhtiar Ahmad , Wali Khan Mashwani

Let $\mathcal{P}$ denote the Carath\'{e}odory class accommodating all the analytic functions $p$ having positive real part and satisfying $p(0)=1$. In this paper, the second coefficient of the normalized analytic function $f$ defined on the…

Complex Variables · Mathematics 2023-05-26 Meghna Sharma , Naveen Kumar Jain , Sushil Kumar

In this article we consider a family $\mathcal{C}(A, B)$ of analytic and locally univalent functions on the open unit disc $\ID=\{z :|z|<1\}$ in the complex plane that properly contains the well-known Janowski class of convex univalent…

Complex Variables · Mathematics 2015-04-29 Bappaditya Bhowmik

Let $T$ be a power-bounded operator on a Banach space $X$, $\mathcal{A}$ be a Banach algebra of bounded holomorphic functions on the unit disc $\mathbb{D}$, and assume that there is a bounded functional calculus for the operator $T$, so…

Functional Analysis · Mathematics 2024-09-10 Charles Batty , David Seifert

Let $\mathcal{S}$ denote the family of all functions that are analytic and univalent in the unit disk $\mathbb{D}:=\{z: |z|<1\}$ and satisfy $f(0)=f^{\prime}(0)-1=0$. In the present paper, we consider certain subclasses of univalent…

Complex Variables · Mathematics 2020-03-24 Lei Shi , Zhi-Gang Wang , Ren-Li Su , Muhammad Arif

In this paper, we determine the radii of $\beta -$uniformly convex of order $\alpha $ for three kinds of normalized Lommel and Struve functions of the first kind. In the cases considered the normalized Lommel and Struve functions are $\beta…

Complex Variables · Mathematics 2017-11-27 Sercan Topkaya , Erhan Deniz , Murat Çağlar

Let ${\mathcal U}^+$ be the class of analytic functions $f$ such that $\frac{z}{f(z)}$ has real and positive coefficients and $f^{-1}$ be its inverse. In this paper we give sharp estimates of the initial coefficients and initial logarithmic…

Complex Variables · Mathematics 2022-01-03 Milutin Obradović , Nikola Tuneski

For $0<\lambda\le 1$, let $\mathcal{U}(\lambda)$ be the class analytic functions $f(z)= z+\sum_{n=2}^{\infty}a_n z^n$ in the unit disk $\mathbb{D}$ satisfying $|f'(z)(z/f(z))^2-1|<\lambda$ and $\mathcal{U}:=\mathcal{U}(1)$. In the present…

Complex Variables · Mathematics 2020-06-30 Md Firoz Ali , Vasudevarao Allu , Hiroshi Yanagihara

In this paper, we obtain the Fekete-Szeg\"{o} problem for the $k$-th $(k\geq1)$ root transform of the analytic and normalized functions $f$ satisfying the condition \begin{equation*} 1+\frac{\alpha-\pi}{2 \sin \alpha}< {\rm…

Complex Variables · Mathematics 2019-05-22 Hesam Mahzoon

Inspired by the recent works of Srivastava et al. (2010), Frasin and Aouf (2011), and Caglar et al. (2013), we introduce and investigate in the present paper two new general subclasses of the class consisting of normalized analytic and…

Complex Variables · Mathematics 2021-02-18 Feras Yousef , Somaia Alroud , Mohamed Illafe

In this article, we study the Bohr operator for the operator valued subordination class $S(f)$ consisting of holomorphic functions subordinate to $f$ in the unit disk $\mathbb{D}:=\{z \in \mathbb{C}: |z|<1\}$, where $f:\mathbb{D}…

Complex Variables · Mathematics 2026-04-15 Vasudevarao Allu , Himadri Halder

We deal with different kinds of generalizations of $\mathcal{S}^*(\psi)$, the class of Ma-Minda starlike functions, in addition to a majorization result of $\mathcal{C}(\psi),$ the class of Ma-Minda convex functions, which are enlisted as…

Complex Variables · Mathematics 2022-08-23 S. Sivaprasad Kumar , Kamaljeet Gangania

The radii of starlikeness and convexity associated with lemniscate of Bernoulli and the Janowski function, $(1+Az)/(1+Bz)$ for $-1\leq B<A\leq 1$, have been determined for normalizations of $q$-Bessel function, Bessel function of first kind…

Complex Variables · Mathematics 2019-06-14 Vibha Madaan , Ajay Kumar , V. Ravichandran

Let $\mathbb{D}:=\{z\in \mathbb{C}: |z|<1\}$ be the unit disk. For $0<\alpha <1$, let $f_{\alpha}(z)=z/(1-z^\alpha)$ for $z \in \mathbb{D}$. We consider the class $\mathcal{F}$ of analytic functions $f_{\alpha}$ which satisfy $\Re…

Complex Variables · Mathematics 2022-09-22 Jnana Preeti Parlapalli , Vasudevarao Allu

For $f(z) = \sum_{n=0}^{\infty} a_n z^n$ and a fixed $z$ in the unit disk, $|z| = r,$ the Bohr operator $\mathcal{M}_r$ is given by \[\mathcal{M}_r (f) = \sum_{n=0}^{\infty} |a_n| |z^n| = \sum_{n=0}^{\infty} |a_n| r^n.\] This papers…

Complex Variables · Mathematics 2019-12-30 Yusuf Abu-Muhanna , Rosihan M. Ali , See Keong Lee
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