English
Related papers

Related papers: Univalent harmonic mappings with integer or half-i…

200 papers

Convolutions or Hadamard products of analytic functions is a well explored area of research and many nice results are available in literature. On the other hand, very little is known in general about the convolutions of univalent harmonic…

Complex Variables · Mathematics 2019-11-07 Chinu Singla , Sushma Gupta , Sukhjit Singh

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

We investigate improved forms of the Bohr inequality, using the quantity $S_r/\pi$, for analytic selfmaps in class $\mathcal{B}$ of $\mathbb{D}$, where $S_r$ is the area measure of $\mathbb{D}_r$. We then generalize the inequality for…

Complex Variables · Mathematics 2025-10-28 Molla Basir Ahamed , Partha Pratim Roy , Sujoy Majumder

Let $\ast$ and $\widetilde {\ast}$ denote the convolution of two analytic maps and that of an analytic map and a harmonic map respectively. Pokhrel [1] proved that if $f = h+\overline{g}$ is a harmonic map convex in the direction of…

Complex Variables · Mathematics 2014-01-03 Raj Kumar , Sushma Gupta , Sukhjit Singh

Musical chords, harmonies or melodies in Just Intonation have note frequencies which are described by a base frequency multiplied by rational numbers. For any local section, these notes can be converted to some base frequency multiplied by…

Sound · Computer Science 2017-01-25 David Ryan

Let $\mathcal{S}_u^*$ denote the class of all analytic functions $f$ in the unit disk $\mathbb{D}:=\{z\in\mathbb{C}:|z|<1\}$, normalized by $f(0)=f'(0)-1=0$ that satisfies the inequality $\left|zf'(z)/f(z)-1\right|<1$ in $\mathbb{D}$. In…

Complex Variables · Mathematics 2025-03-19 Md Firoz Ali , Md Nurezzaman

This paper treats the class of normalized logharmonic mappings f(z) = zh(z)bar{g(z)} in the unit disk satisfying {\phi}(z) = zh(z)g(z) is analytically typically real. Every such mapping f is shown to be a product of two particular…

Complex Variables · Mathematics 2017-10-05 Najla M. Alarifi , Zayid Abdulhadi , Rosihan M. Ali

The logarithmic coefficients $\gamma_n$ of an analytic and univalent function $f$ in the unit disk $\mathbb{D}=\{z\in\mathbb{C}:|z|<1\}$ with the normalization $f(0)=0=f'(0)-1$ is defined by $\log \frac{f(z)}{z}= 2\sum_{n=1}^{\infty}…

Complex Variables · Mathematics 2017-05-16 Md Firoz Ali , A. Vasudevarao

A harmonic mapping is a univalent harmonic function of one complex variable. We define a family of harmonic mappings on the unit disk whose images are rotationally symmetric rosettes with $n$ cusps or n nodes, where $n \ge 3$. These…

Complex Variables · Mathematics 2021-06-08 Jane McDougall , Lauren Stierman

The aim of this paper is to obtain the Schwarz-Pick type inequality for $\alpha$-harmonic functions $f$ in the unit disk and get estimates on the coefficients of $f$. As an application, a Landau type theorem of $\alpha$-harmonic functions…

Complex Variables · Mathematics 2017-05-30 Peijin Li , Xiantao Wang , Qianhong Xiao

Integrally convex functions constitute a fundamental function class in discrete convex analysis. This paper shows that an integer-valued integrally convex function admits an integral subgradient and that the integral biconjugate of an…

Combinatorics · Mathematics 2018-09-11 Kazuo Murota , Akihisa Tamura

For an analytic and univalent function $f$ in the unit disk $\mathbb{D}:=\{z\in\mathbb{C}:|z|<1\}$ with the normalization $f(0)=0=f'(0)-1$, the logarithmic coefficients $\gamma_n$ are defined by $\log \frac{f(z)}{z}= 2\sum_{n=1}^{\infty}…

Complex Variables · Mathematics 2016-10-03 Md Firoz Ali , D. K. Thomas , A. Vasudevarao

Let $f=h+\overline{g}$ be a harmonic univalent map in the unit disk $\mathbb{D}$, where $h $ and $g$ are analytic. We obtain an improved estimate for the second coefficient of $h$. This indeed is the first qualitative improvement after the…

Complex Variables · Mathematics 2018-07-17 Yusuf Abu Muhanna , Rosihan M. Ali , Saminathan Ponnusamy

Given a strictly positive measure, we characterize inner semicontinuous solid convex-valued mappings for which continuous functions which are selections almost everywhere are selections. This class contains continuous mappings as well as…

Optimization and Control · Mathematics 2013-08-23 Ari-Pekka Perkkiö

In this paper, we introduce a new subclass of harmonic functions $f=s+\overline{t}$ in the open unit disk $U =\left \{ z\in C:\left \vert z\right \vert <1\right \} $ satisfying ${\text{Re}}\left[ \gamma s^{\prime }(z)+\delta zs^{\prime…

Complex Variables · Mathematics 2021-07-09 Serkan Çakmak , Elif Yaşar , Sibel Yalçın

In this article, we establish the Bohr inequalities for the sense-preserving $K$-quasiconformal harmonic mappings defined in the unit disk $\mathbb{D}$ involving classes of Ma-Minda starlike and convex univalent functions, usually denoted…

Complex Variables · Mathematics 2021-10-26 Kamaljeet Gangania

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

At the end of 1960's, Lawrence Zalcman posed a conjecture that the coefficients of univalent functions $f(z) = z + \sum\limits_2^\infty a_n z^n$ on the unit disk satisfy the sharp inequality $|a_n^2 - a_{2n-1}| \le (n-1)^2$, with equality…

Complex Variables · Mathematics 2012-10-29 Samuel L. Krushkal

The purpose of this work is to present a class of harmonic univalent functions defined by the Dziok-Srivastava operator. Some geometric properties like coefficients conditions, distortion theorem, convolution (Hadamard product), convex…

Complex Variables · Mathematics 2026-02-25 Mays S. Abdul Ameer , Abdul Rahman S. Juma , Raheam A. Al-Saphory

In this paper we consider some properties of the initial logarithmic coefficients for inverse functions of functions univalent in the unit disc. The case of convex functions is treated separately. We give estimate, in some cases sharp, of…

Complex Variables · Mathematics 2026-05-15 Milutin Obradović , Nikola Tuneski , Paweł Zaprawa
‹ Prev 1 4 5 6 7 8 10 Next ›