نتایج جستجو برای: harmonic univalent functions

تعداد نتایج: 533880  

2014

Harmonic univalent mappings have attracted the serious attention of complex analysts only after the appearance of a basic paper by Clunie and Sheil-Small [4] in 1984. These researchers laid the foundation for the study of harmonic univalent mappings over the unit disk as a generalization of analytic univalent functions. Interestingly, almost at the same time, the famous Bieberbach conjecture wh...

Journal: :Applied Mathematics and Computation 2003
Sibel Yalçin Metin Öztürk Mümin Yamankaradeniz

Abstract In this paper we introduce a new family Ā(α, β, γ) of harmonic univalent functions with negative coefficients using fractional calculus operator Ωλwhich contains various well known classes of harmonic univalent functions as well as many new ones. We obtain coefficient estimate, distortion theorem and various other properties for functions belonging to the class Ā(α, β, γ) in the unit d...

Journal: :Int. J. Math. Mathematical Sciences 2007
Jay M. Jahangiri Herb Silverman Evelyn M. Silvia

Complex-valued harmonic functions that are univalent and sense-preserving in the open unit disk can be written in the form f = h+ g, where h and g are analytic in the open unit disk. The functions h and g are called the analytic and coanalytic parts of f , respectively. In this paper, we construct certain planar harmonic maps either by varying the coanalytic parts of harmonic functions that are...

‎Complex-valued harmonic functions that are univalent and‎ ‎sense-preserving in the open unit disk $U$ can be written as form‎ ‎$f =h+bar{g}$‎, ‎where $h$ and $g$ are analytic in $U$‎. ‎In this paper‎, ‎we introduce the class $S_H^1(beta)$‎, ‎where $1<betaleq 2$‎, ‎and‎ ‎consisting of harmonic univalent function $f = h+bar{g}$‎, ‎where $h$ and $g$ are in the form‎ ‎$h(z) = z+sumlimits_{n=2}^inf...

2008
Saurabh Porwal

The class of univalent harmonic functions on the unit disc satisfying the condition ∑∞ k=2 (k m − αk)(|ak|+ |bk|) ≤ (1−α)(1−|b1|) is given. Sharp coefficient relations and distortion theorems are given for these functions. In this paper we find that many results of Özturk and Yalcin [5] are incorrect. Some of the results of this paper correct the theorems and examples of [5]. Further, sharp coe...

2004
JAY M. JAHANGIRI

Sufficient coefficient conditions for complex functions to be close-to-convex harmonic or convex harmonic are given. Construction of close-to-convex harmonic functions is also studied by looking at transforms of convex analytic functions. Finally, a convolution property for harmonic functions is discussed. Harmonic, Convex, Close-to-Convex, Univalent.

2012
Amit Kumar Yadav A. K. Yadav

The aim of this article is to study a multiplier family of univalent harmonic meromorphic functions using the sequences {cn} and {dn} of positive real numbers. By specializing {cn} and {dn}, representation theorms, bounds, convolution, geometric convolution, integral convolution and convex combinations for such functions have been determined. The theorems presented, in many cases, confirm or ge...

Journal: :Journal of Taibah University for Science 2021

The convolution of convex harmonic univalent functions in the unit disk, unlike analytic functions, may not be or even univalent. main purpose this work is to develop previous in...

‎In this paper‎, ‎we study the convex combinations of harmonic mappings obtained by shearing a class of slit conformal mappings‎. ‎Sufficient conditions for the convex combinations of harmonic mappings of this family to be univalent and convex in the horizontal direction are derived‎. ‎Several examples of univalent harmonic mappings constructed by using these methods are presented to illustrate...

2008
Hakan Bostancı Metin Öztürk

In this paper, a necessary and sufficient coefficient are given for functions in a class of complex valued meromorphic harmonic univalent functions of the form f = h + ḡ using Salagean operator. Furthermore, distortion theorems, extreme points, convolution condition and convex combinations for this family of meromorphic harmonic functions are obtained. Keywords—Harmonic mappings, Meromorphic fu...

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