Analysis and Mathematical Physics ( IF 1.7 ) Pub Date : 2021-07-31 , DOI: 10.1007/s13324-021-00579-0 Rahim Kargar 1 , Lucyna Trojnar-Spelina 2
In this paper we study some properties of functions f which are analytic and normalized (i.e. \(f(0)=0=f'(0)-1\)) such that satisfy the following subordination relation
$$\begin{aligned} \left( \frac{zf'(z)}{f(z)}-1\right) \prec \frac{z}{(1-pz)(1-qz)}, \end{aligned}$$where \((p,q) \in [-1,1] \times [-1,1]\). These types of functions are starlike related to the generalized Koebe function. Some of the features are: radius of starlikeness of order \(\gamma \in [0,1)\), image of \(f\left( \{z:|z|<r\}\right) \) where \(r\in (0,1)\), radius of convexity, estimation of initial and logarithmic coefficients, and Fekete–Szegö problem.
中文翻译:
与广义 Koebe 函数相关的星状函数
在本文中,我们研究了解析和归一化的函数f 的一些性质(即\(f(0)=0=f'(0)-1\))满足以下从属关系
$$\begin{aligned} \left( \frac{zf'(z)}{f(z)}-1\right) \prec \frac{z}{(1-pz)(1-qz)}, \end{对齐}$$其中\((p,q) \in [-1,1] \times [-1,1]\)。这些类型的函数与广义 Koebe 函数呈星状相关。的一些功能是:为了星形性的半径\(\伽玛\在[0,1)\)的,图像\(F \左(\ {Z:| Z | <R \} \右)\) ,其中\(r\in (0,1)\)、凸面半径、初始和对数系数的估计以及 Fekete-Szegö 问题。