论文标题
类$ \ mathcal {u} $和常规类$ \ Mathcal {S} $的第二种类型的Hankel决定因素
Two types of the second Hankel determinant for the class $\mathcal{U}$ and the general class $\mathcal{S}$
论文作者
论文摘要
在本文中,我们确定特殊类型$ h_ {2}(3)(f)$和$ h_ {2}(4)(f)$的汉克尔决定因素的上限,用于单价函数的类别以及$ \ mathcal {u} $ class $ \ mathcal {u} $由\ [\ nathcal { \left|\left[\frac{z}{f(z)}\right]^2 f'(z)-1 \right|<1,\, z\in{\mathbb D} \right\}, \] where $\mathcal{A}$ is the class of functions analytic in the unit disk ${\mathbb D}$ and normalized such that $ f(z)= z+a_2z^2+\ cdots $。
In this paper we determine the upper bounds of the Hankel determinants of special type $H_{2}(3)(f)$ and $H_{2}(4)(f)$ for the class of univalent functions and for the class $\mathcal{U}$ defined by \[ \mathcal{U}=\left\{ f\in\mathcal{A} : \left|\left[\frac{z}{f(z)}\right]^2 f'(z)-1 \right|<1,\, z\in{\mathbb D} \right\}, \] where $\mathcal{A}$ is the class of functions analytic in the unit disk ${\mathbb D}$ and normalized such that $f(z)=z+a_2z^2+\cdots$.