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Related papers: Some properties of univalent log-harmonic mappings

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We study the $k$-fold symmetric starlike univalent logharmonic mappings of the form $f(z)=zh(z)\overline{g(z)}$ in the unit disk $\mathbb{D}:= \lbrace z \in \mathbb{C}: |z|<1 \rbrace$ with several examples, where $h(z)=\exp…

Complex Variables · Mathematics 2023-08-15 Akash Meher , Priyabrat Gochhayat

We consider the class univalent log-harmonic mappings on the unit disk. Firstly, we obtain necessary and sufficient conditions for a complex-valued continuous function to be starlike or convex in the unit disk. Then we present a general…

Complex Variables · Mathematics 2019-05-28 ZhiHong Liu , Saminathan Ponnusamy

In this paper, we introduce definitions of the pre-Schwarzian and the Schwarzian derivatives for any locally univalent log-harmonic mappings defined in the unit disk $\mathbb{D}=\{z\in\mathbb{C}: |z|<1\}$. We explore the properties and…

Complex Variables · Mathematics 2025-11-10 Raju Biswas , Rajib Mandal

In this note, we consider certain logharmonic mappings in the unit disk $\mathbb{D}=\{z\in\mathbb{C}:|z|<1\}.$ Next, we obtain sharp bound of pre-Schwarzian norm of such logharmonic mappings in the unit disk. Then we discuss growth theorem…

Complex Variables · Mathematics 2025-05-21 Sushil Pandit

We connect the pre-Schwarzian norm of logharmonic mappings to the pre-Schwarzian norm of an analytic function and establish some necessary and sufficient conditions under which locally univalent logharmonic mappings have a finite…

Complex Variables · Mathematics 2023-08-25 Md Firoz Ali , Sushil Pandit

In this paper, we find the radius of the disk $\Omega _{r}$ such that every starlike logharmonic mapping $f(z)$ of order $\alpha ,$ is starlike in $% |z|\leq r$ with respect to any point of $\Omega _{r}.$ We also establish a relation…

Complex Variables · Mathematics 2016-10-05 Zayid Abdulhadi , Layan El Hajj

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

In this paper, we consider the class of uniformly locally univalent harmonic mappings in the unit disk and build a relationship between its pre-Schwarzian norm and uniformly hyperbolic radius. Also, we establish eight ways of characterizing…

Complex Variables · Mathematics 2018-01-08 Gang Liu , Saminathan Ponnusamy

Let $ \mathcal{H}(\mathbb{D}) $ be the linear space of analytic functions on the unit disk $ \mathbb{D}=\{z\in\mathbb{C}: |z|<1\} $ and let $ \mathcal{B}=\{w\in \mathcal{H}(\mathbb{D}: |w(z)|<1)\} $. The classical Bohr's inequality states…

Complex Variables · Mathematics 2021-03-16 Molla Basir Ahamed , Vasudevarao Allu

The primary aim of this article is to extend certain inequalities concerning the pre-Schwarzian derivatives from the case of analytic univalent functions to that of univalent harmonic mappings defined on certain domains. This is done in two…

Complex Variables · Mathematics 2017-07-07 Gang Liu , Saminathan Ponnusamy

The aim of this paper is twofold. One is to introduce the class of harmonic $\nu$-Bloch-type mappings as a generalization of harmonic $\nu$-Bloch mappings and thereby we generalize some recent results of harmonic $1$-Bloch-type mappings…

Complex Variables · Mathematics 2017-07-07 Gang Liu , Saminathan Ponnusamy

We introduce a new definition of pre-Schwarzian derivative for logharmonic mappings and basic properties such as the chain rule, multiplicative invariance and affine invariance are proved for these operators. It is shown that the…

Complex Variables · Mathematics 2020-06-16 V. Bravo , R. Hernandez , O. Venegas

In this paper, a class of $\log$-polyharmonic mappings $\mathcal{L}_p\mathcal{H}$ together with its subclass $\mathcal{L}_p\mathcal{H}(G)$ in the unit disk $\mathbb{D}=\{z: |z|<1\}$ is introduced, and several geometrical properties such as…

Complex Variables · Mathematics 2016-11-08 Jiaolong Chen , Bin Sheng , Xiaotao Wang

Let $f(z)=h(z)+\overline{g(z)}$ be a harmonic mapping of the unit disk $U$. In this paper, the sharp coefficient estimates for bounded planar harmonic mappings are established, the sharp coefficient estimates for normalized planar harmonic…

Complex Variables · Mathematics 2015-11-17 Ming-Sheng Liu , Zhi-Wen Liu , Yu-Can Zhu

A pre-Schwarzian and a Schwarzian derivative for locally univalent pluriharmonic mappings in ${\mathbb C}^n$ are introduced. Basic properties such as the chain rule, multiplicative invariance and affine invariance are proved for these…

Complex Variables · Mathematics 2020-10-19 Iason Efraimidis , Álvaro Ferrada-Salas , Rodrigo Hernández , Rodrigo Vargas

In this paper we introduce a definition of the pre-Schwarzian and the Schwarzian derivatives of any locally univalent harmonic mapping $f$ in the complex plane without assuming any additional condition on the (second complex) dilatation…

Complex Variables · Mathematics 2012-10-09 Rodrigo Hernández , María J. Martín

In this paper, we first obtain an estimate of the coefficients for $\alpha$-harmonic mappings. By applying these coefficient estimates, we prove the Landau type theorem for $\alpha$-harmonic mappings defined on the unit disc $\ID$.

Complex Variables · Mathematics 2024-06-07 Vasudevarao Allu , Rohit Kumar

In this paper, we first establish the Schwarz-Pick lemma of higher-order and apply it to obtain a univalency criteria for planar harmonic mappings. Then we discuss distortion theorems, Lipschitz continuity and univalency of planar harmonic…

Complex Variables · Mathematics 2014-04-17 Shaolin Chen , Saminathan Ponnusamy , Antti Rasila , Xiantao Wang

In this paper, we first find an estimate for the range of polyharmonic mappings in the class $HC_{p}^{0}$. Then, we obtain two characterizations in terms of the convolution for polyharmonic mappings to be starlike of order $\alpha$, and…

Complex Variables · Mathematics 2014-06-18 Jiaolong Chen , Antti Rasila , Xiantao Wang

In this article we prove Bohr inequalities for sense-preserving $K$-quasiconformal harmonic mappings defined in $\mathbb{D}$ and obtain the corresponding results for sense-preserving harmonic mappings by letting $K\to\infty$. One of the…

Complex Variables · Mathematics 2021-01-12 Bappaditya Bhowmik , Nilanjan Das
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