scholarly journals Distortion and covering theorems of pluriharmonic mappings

Filomat ◽  
2017 ◽  
Vol 31 (9) ◽  
pp. 2749-2762
Author(s):  
Shaolin Chen ◽  
Saminathan Ponnusamy
Keyword(s):  
Analytic Functions ◽  
Harmonic Mappings ◽  
Classical Approach ◽  
Covering Theorems ◽  
Linear Invariant ◽  
Planar Harmonic Mappings

The linear-invariant families of analytic functions make it possible to obtain well-known results to broader classes of functions, and are often helpful in obtaining simpler proofs along with new results. Based on this classical approach due to Pommerenke, properties (such as bounds for the derivative, covering and distortion) of a corresponding class of locally quasiconformal and planar harmonic mappings are established by Starkov. Motivated by these works, in this paper, we mainly investigate distortion and covering theorems on some classes of pluriharmonic mappings.

scholarly journals Schwarzian derivative criteria for valence of analytic and harmonic mappings

2007 ◽  
Vol 143 (2) ◽  
pp. 473-486 ◽  
Author(s):  
MARTIN CHUAQUI ◽  
PETER DUREN ◽  
BRAD OSGOOD
Keyword(s):  
Unit Disk ◽  
Minimal Surfaces ◽  
Analytic Functions ◽  
Schwarzian Derivative ◽  
Harmonic Mappings ◽  
Planar Harmonic Mappings

AbstractFor analytic functions in the unit disk, general bounds on the Schwarzian derivative in terms of Nehari functions are shown to imply uniform local univalence and in some cases finite and bounded valence. Similar results are obtained for the Weierstrass–Enneper lifts of planar harmonic mappings to their associated minimal surfaces. Finally, certain classes of harmonic mappings are shown to have finite Schwarzian norm.

scholarly journals Planar harmonic mappings in a family of functions convex in one direction

Filomat ◽  
2021 ◽  
Vol 35 (2) ◽  
pp. 431-445
Author(s):  
Sudhananda Maharan ◽  
Swadesh Sahoo
Keyword(s):  
Unit Disk ◽  
Analytic Functions ◽  
Harmonic Mapping ◽  
Harmonic Mappings ◽  
Open Unit ◽  
Open Unit Disk ◽  
Optimal Estimates ◽  
Convex In One Direction ◽  
Planar Harmonic Mappings ◽  
Class Of Functions

Let D := {z ? C : |z| < 1} be the open unit disk, and h and 1 be two analytic functions in D. Suppose that f = h + ?g is a harmonic mapping in D with the usual normalization h(0) = 0 = g(0) and h'(0) = 1. In this paper, we consider harmonic mappings f by restricting its analytic part to a family of functions convex in one direction and, in particular, starlike. Some sharp and optimal estimates for coefficient bounds, growth, covering and area bounds are investigated for the class of functions under consideration. Also, we obtain optimal radii of fully convexity, fully starlikeness, uniformly convexity, and uniformly starlikeness of functions belonging to those family.

scholarly journals On Certain Subclasses of Analytic Functions Defined by Differential Subordination

2011 ◽  
Vol 2011 ◽  
pp. 1-10
Author(s):  
Hesam Mahzoon
Keyword(s):  
Analytic Functions ◽  
Differential Subordination ◽  
Radius Of Starlikeness ◽  
Covering Theorems ◽  
Coefficient Inequalities

We introduce and study certain subclasses of analytic functions which are defined by differential subordination. Coefficient inequalities, some properties of neighborhoods, distortion and covering theorems, radius of starlikeness, and convexity for these subclasses are given.

Majorization-Subordination Theorems for Locally Univalent Functions, II

1973 ◽  
Vol 25 (2) ◽  
pp. 420-425 ◽  
Author(s):  
Douglas Michael Campbell
Keyword(s):  
Analytic Functions ◽  
Unit Disc ◽  
Univalent Functions ◽  
Open Unit ◽  
Open Unit Disc ◽  
The Family ◽  
Linear Invariant ◽  
Linear Invariant Family

Let denote the set of all normalized analytic univalent functions in the open unit disc D. Let f(z), F(z) and φ(z) be analytic in |z| < r. We say that f(z) is majorized by F(z) in we say that f(z) is subordinate to F(z) in where .Let be the set of all locally univalent (f’(z) ≠ 0) analytic functions in D with order ≦α which are of the form f(z) = z +… . The family is known as the universal linear invariant family of order α [6]. A concise summary of and introduction to properties of linear invariant families which relate to the following material is contained in [1]. The present paper contains the proofs of some of the results announced in [1]

Some Covering Theorems for Analytic Functions

1979 ◽  
Vol s2-19 (1) ◽  
pp. 93-101 ◽  
Author(s):  
D. A. Brannan ◽  
W. E. Kirwan
Keyword(s):  
Analytic Functions ◽  
Covering Theorems
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