학술논문

On Certain Generalizations of $\mathcal{S}^*(\psi)$
Document Type
Working Paper
Source
Comput. Methods Funct. Theory 22, 215 -227, 2022
Subject
Mathematics - Complex Variables
Language
Abstract
We deal with different kinds of generalizations of $\mathcal{S}^*(\psi)$, the class of Ma-Minda starlike functions, in addition to a majorization result of $\mathcal{C}(\psi),$ the class of Ma-Minda convex functions, which are enlisted as follows: 1. Let $h$ be an analytic function, $f$ be in $\mathcal{C}(\psi)$ and $h$ be majorized by $f$ in the unit disk $\mathbb{D},$ then for a given $\psi,$ we derive a general equation, which yields the radius constant $r_{\psi}$ such that $|h'(z)|\leq |f'(z)|$ in $|z|\leq r_{\psi}$. Consequently, obtain results associating $\mathcal{S}^*(\psi)$ and others. 2. We find the largest radius $r_0$ so that the product function $g(z)h(z)/z$ belongs to a desired class for $|z|Comment: All the results under the Majorization section have been proved to be sharp in this version