Distortion, Radius of Concavity and Several Other Radii Results for Certain Classes of Functions

Let S(p) be the class of all meromorphic univalent functions defined in the unit disc D of the complex plane with a simple pole at z=p and normalized by the conditions f(0)=0 and f′(0)=1. In this article, we establish an estimate of the quantity |zf′/f| and obtain the region of variability of the fu...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Computational methods and function theory Jg. 25; H. 2; S. 393 - 418
Hauptverfasser: Bhowmik, Bappaditya, Biswas, Souvik
Format: Journal Article
Sprache:Englisch
Veröffentlicht: Heidelberg Springer Nature B.V 01.06.2025
Schlagworte:
ISSN:1617-9447, 2195-3724
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Let S(p) be the class of all meromorphic univalent functions defined in the unit disc D of the complex plane with a simple pole at z=p and normalized by the conditions f(0)=0 and f′(0)=1. In this article, we establish an estimate of the quantity |zf′/f| and obtain the region of variability of the function zf′′/f′ for z∈D, f∈S(p). After that, we define radius of concavity and compute the same for functions in S(p) and for some other well-known classes of functions. We also explore linear combinations of functions belonging to S(p) and some other classes of analytic univalent functions and investigate their radii of univalence, convexity and concavity.
Bibliographie:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 14
ISSN:1617-9447
2195-3724
DOI:10.1007/s40315-024-00525-8