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Related papers: Radii problems for Ma-Minda Starlikeness

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In this paper, we consider the Ma-Minda classes of analytic functions $\mathcal{S}^{*}(\phi):= \{f\in \mathcal{A} : ({zf'(z)}/{f(z)}) \prec \phi(z) \}$ and $\mathcal{C}(\phi):= \{f\in \mathcal{A} : (1+{zf''(z)}/{f'(z)}) \prec \phi(z) \}$…

Complex Variables · Mathematics 2023-07-25 S. Sivaprasad Kumar , Kamaljeet Gangania

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

In this paper, we prove various radius results and obtain sufficient conditions using the convolution for the Ma-Minda classes $\mathcal{S}^*(\psi)$ and $\mathcal{C}(\psi)$ of starlike and convex analytic functions. We also obtain the Bohr…

Complex Variables · Mathematics 2021-06-10 Kamaljeet Gangania , S. Sivaprasad Kumar

Ma-Minda class (of starlike functions) consists of all normalized analytic functions $f$ on the unit disk for which the image of $zf'(z)/f(z)$ is contained in the some starlike region in the right-half plane. We obtain the best possible…

Complex Variables · Mathematics 2019-10-14 Adiba Naz , Sushil Kumar , V. Ravichandran

A starlike univalent function $f$ is characterized by the function $zf'(z)/f(z)$; several subclasses of these functions were studied in the past by restricting the function $zf'(z)/f(z)$ to take values in a region $\Omega$ on the right-half…

Complex Variables · Mathematics 2021-01-06 Shalu Yadav , Kanika Sharma , V. Ravichandran

We find the radius of starlikeness of order $\alpha$, $0\leq \alpha<1$, of normalized analytic functions $f$ on the unit disk satisfying either $\operatorname{Re}(f(z)/g(z))>0$ or $\left| (f(z)/g(z))-1\right|<1$ for some close-to-star…

Complex Variables · Mathematics 2020-03-13 R. Kanaga , V. Ravichandran

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

We investigate the non-univalent function's properties reminiscent of the theory of univalent starlike functions. Let the analytic function $\psi(z)=\sum_{i=1}^{\infty}A_i z^i$, $A_1\neq0$ be univalent in the unit disk. Non-univalent…

Complex Variables · Mathematics 2022-08-02 Kamaljeet Gangania

For a function $f$ starlike of order $\alpha$, $0\leqslant \alpha <1$, a non-constant polynomial $Q$ of degree $n$ which is non-vanishing in the unit disc $\mathbb{D}$ and $\beta>0$, we consider the function $F:\mathbb{D}\to\mathbb{C}$…

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

We investigate harmonic mappings $f=h+\bar{g}$ defined in the unit disk, where $g$ and $h$ satisfy certain prescribed conditions and the analytic part $h$ belongs to the Ma and Minda class of starlike functions. Certain sharp radius results…

Complex Variables · Mathematics 2022-08-02 Kamaljeet Gangania

In the present investigation, we study the class of Sigmoid starlike functions, given by $\mathcal{S}^*_{SG}=\{f\in\mathcal{A}: {zf'(z)}/{f(z)}\prec 2/(1+e^{-z})\}$ in context of estimating the sharp radius constants associated with several…

Complex Variables · Mathematics 2022-08-03 Priyanka Goel , S. Sivaprasad Kumar

Let $\mathcal{S}^*_{Ne}$ be the collection of all analytic functions $f(z)$ defined on the open unit disk $\mathbb{D}$ and satisfying the normalizations $f(0)=f'(0)-1=0$ such that the quantity $zf'(z)/f(z)$ assumes values from the range of…

Complex Variables · Mathematics 2021-04-13 Lateef Ahmad Wani , A. Swaminathan

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

This paper deals with a special type of Ma-Minda function introduced here with many fascinating facts and interesting applications. It is much akin in all aspects but differs by a condition from its Ma-Minda counterpart. Further, we…

Complex Variables · Mathematics 2022-04-05 S. Sivaprasad Kumar , Shagun Banga

In the past several subclasses of starlike functions are defined involving real part and modulus of certain expressions of functions under study, combined by way of an inequality. In the similar fashion, we introduce a new class…

Complex Variables · Mathematics 2021-08-25 S. Sivaprasad Kumar , Shagun Banga

For $0\leq \alpha <1$, the sharp radii of starlikeness and convexity of order $\alpha$ for functions of the form $f(z)=z+a_2z^2+a_3z^3+...$ whose Taylor coefficients $a_n$ satisfy the conditions $|a_2|=2b$, $0\leq b\leq 1$, and $|a_n|\leq n…

Complex Variables · Mathematics 2011-08-30 V. Ravichandran

We consider three classes of functions defined using the class $\mathcal{P}$ of all analytic functions $p(z)=1+cz+\dotsb$ on the open unit disk having positive real part and study several radius problems for these classes. The first class…

Complex Variables · Mathematics 2020-07-21 Adam Lecko , V. Ravichandran , Asha Sebastian

Geometric properties of the classical Lommel and Struve functions, both of the first kind, are studied. For each of them, there different normalizations are applied in such a way that the resulting functions are analytic in the unit disc of…

Classical Analysis and ODEs · Mathematics 2017-07-14 Árpád Baricz , Dimitar K. Dimitrov , Halit Orhan , Nihat Yagmur

In this paper we deal with the radii of starlikeness and convexity of the $q-$Mittag--Leffler function for three different kinds of normalization by making use of their Hadamard factorization in such a way that the resulting functions are…

Complex Variables · Mathematics 2019-07-17 Evrim Toklu

Geometric function theory increasingly draws on $q$-calculus to model discrete and quantum-inspired phenomena. Motivated by this, the present paper introduces new subclasses of analytic functions: the class $\mathcal{S}^{*}_{\xi_q}$ of…

Complex Variables · Mathematics 2026-05-26 S. Sivaprasad Kumar , Snehal Pannu
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