Some properties of subclasses of spiral-like functions involving beta-negative binomial distribution

UDC 517.53 By using beta-negative binomial distribution, we introduce two novel subclasses of spiral-like functions; namely,  spiral-starlike functions and spiral-convex functions denoted by $S^{\eta}_{\lambda, \gamma, \mu}(\alpha, \beta)$ and $E^{\eta}_{\lambda, \gamma, \mu}(\alpha, \beta),$ respec...

Full description

Saved in:
Bibliographic Details
Date:2026
Main Authors: Pattnayak, Eureka, Panigrahi, Trailokya, El-Ashwah, Rabha M.
Format: Article
Language:English
Published: Institute of Mathematics, NAS of Ukraine 2026
Online Access:https://umj.imath.kiev.ua/index.php/umj/article/view/9343
Tags: Add Tag
No Tags, Be the first to tag this record!
Journal Title:Ukrains’kyi Matematychnyi Zhurnal
Download file: Pdf

Institution

Ukrains’kyi Matematychnyi Zhurnal
Description
Summary:UDC 517.53 By using beta-negative binomial distribution, we introduce two novel subclasses of spiral-like functions; namely,  spiral-starlike functions and spiral-convex functions denoted by $S^{\eta}_{\lambda, \gamma, \mu}(\alpha, \beta)$ and $E^{\eta}_{\lambda, \gamma, \mu}(\alpha, \beta),$ respectively, and defined in the domain of open unit disk $\mathbb{D}=\{z \in \mathbb{C}\colon |z|<1\}.$ We establish sufficient conditions for functions to be members of families mentioned above. Further, the bounds of some initial coefficients and Fekete–Szegö functionals for the classes described above are obtained.
DOI:10.3842/umzh.v78i3-4.9343