An estimation of the pre-Schwarzian norm for certain classes of analytic functions

Abstract

The primary objective of this paper is to establish the sharp estimates of the pre-Schwarzian norm for functions $f$ in the class $\mathcal{S}^*(\varphi)$ and $\mathcal{C}(\varphi)$ when $\varphi(z)=1/(1-z)^s$ with $0<s\leq 1$ and $\varphi(z)=(1+sz)^2$ with $0<s\leq 1/\sqrt{2}$, where $\mathcal{S}^*(\varphi)$ and $\mathcal{C}(\varphi)$ are the Ma-Minda type starlike and Ma-Minda type convex classes associated with $\varphi$, respectively.