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arXiv · 1909.00139

A normality Criterion for a Family of Meromorphic Functions

Gopal Datt·Sanjay Kumar
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Abstract

Schwick, in [6], states that let $\mathcal{F}$ be a family of meromorphic functions on a domain $D$ and if for each $f\in\mathcal{F}$, $(f^n)^{(k)}\neq 1$, for $z\in D$, where $n, k$ are positive integers such that $n\geq k+3$, then $\mathcal{F}$ is a normal family in $D$. In this paper, we investigate the opposite view that if for each $f\in\mathcal{F}$, $(f^n)^{(k)}(z)-\psi(z)$ has zeros in $D$, where $\psi(z)$ is a holomorphic function in $D$, then what can be said about the normality of the family $\mathcal{F}$?

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Gopal Datt, Sanjay Kumar. 2019-08-31. A normality Criterion for a Family of Meromorphic Functions. https://doi.org/10.1007/s00605-016-0896-y

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