Normality criteria for families of
zero-free meromorphic functions
Annales Polonici Mathematici, Tome 115 (2015) no. 1, pp. 89-98
Let $\mathcal F$ be a family of zero-free meromorphic functions in a domain $D$, let $n$, $k$ and $m$ be positive integers with $n\geq m+1$,\vadjust {\vskip 1pt} and let $a\not =0$ and $b$ be finite complex numbers. If for each $f\in \mathcal F$, $f^m+a(f^{(k)})^n-b$ has at most $nk$ zeros in $D$, ignoring multiplicities, then $\mathcal F$ is normal in $D$. The examples show that the result is sharp.
Keywords:
mathcal family zero free meromorphic functions domain positive integers geq vadjust vskip finite complex numbers each mathcal f n b has zeros ignoring multiplicities mathcal normal examples result sharp
Affiliations des auteurs :
Jun-Fan Chen  1
@article{10_4064_ap115_1_7,
author = {Jun-Fan Chen},
title = {Normality criteria for families of
zero-free meromorphic functions},
journal = {Annales Polonici Mathematici},
pages = {89--98},
year = {2015},
volume = {115},
number = {1},
doi = {10.4064/ap115-1-7},
language = {en},
url = {http://geodesic.mathdoc.fr/articles/10.4064/ap115-1-7/}
}
Jun-Fan Chen. Normality criteria for families of zero-free meromorphic functions. Annales Polonici Mathematici, Tome 115 (2015) no. 1, pp. 89-98. doi: 10.4064/ap115-1-7
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