scholarly journals A Note on Normal Families of Meromorphic Functions Concerning Shared Values

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Yuan Wenjun ◽  
Wei Jinjin ◽  
Lin Jianming

We study the normality of families of meromorphic functions related to a Hayman conjecture. We consider whether a family of meromorphic functionsℱis normal inDif, for every pair of functionsfandginℱ,f′−afnandg′−agnshare the valuebforn=1,2, and 3, whereaandb≠0are two finite complex numbers. Some examples show that the conditions in our results are the best possible.

2010 ◽  
Vol 2010 ◽  
pp. 1-14 ◽  
Author(s):  
Jianming Qi ◽  
Taiying Zhu

LetFbe a family of meromorphic functions in the domainD, all of whose zeros are multiple. Letn  (n≥2)be an integer and leta,bbe two nonzero finite complex numbers. Iff+a(f')nandg+a(g')nsharebinDfor every pair of functionsf,g∈F, thenFis normal inD.


2011 ◽  
Vol 2011 ◽  
pp. 1-9
Author(s):  
Wenjun Yuan ◽  
Bing Zhu ◽  
Jianming Lin

We study the normality of families of meromorphic functions concerning shared values. We consider whether a family of meromorphic functions ℱ is normal inD, if, for every pair of functionsfandgin ℱ,f′−af−nandg′−ag−nshare the valueb, whereaandbare two finite complex numbers such thata≠0,nis a positive integer. Some examples show that the conditions in our results are best possible.


2009 ◽  
Vol 86 (3) ◽  
pp. 339-354 ◽  
Author(s):  
MINGLIANG FANG ◽  
LAWRENCE ZALCMAN

AbstractLet ℱ be a family of meromorphic functions defined in D, all of whose zeros have multiplicity at least k+1. Let a and b be distinct finite complex numbers, and let k be a positive integer. If, for each pair of functions f and g in ℱ, f(k) and g(k) share the set S={a,b}, then ℱ is normal in D. The condition that the zeros of functions in ℱ have multiplicity at least k+1 cannot be weakened.


2013 ◽  
Vol 58 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Jian-Jun Ding ◽  
Li-Wei Ding ◽  
Wen-Jun Yuan

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Xin-Li Wang ◽  
Ning Cui

We study the problem of normal families of meromorphic functions concerning polynomials and shared values. We prove that a family ℱ of meromorphic functions in a domain D is normal if, for each function f∈ℱ, Pfzfkz=a⇔fkz=b, where P is a polynomial with the origin as zero, k is a positive integer, and a ≠0, b are two finite constants.


2016 ◽  
Vol 36 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Wei CHEN ◽  
Honggen TIAN ◽  
Peichu HU

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Wei Chen ◽  
Honggen Tian ◽  
Yingying Zhang ◽  
Wenjun Yuan

We obtain a normal criterion of meromorphic functions concerning, shared values. Let ℱ be a family of meromorphic functions in a domain D and let k,n≥k+2 be positive integers. Let a≠0,b be two finite complex constants. If, for each f∈ℱ, all zeros of f have multiplicity at least k+1 and f+a(f(k))n and g+a(g(k))n share b in D for every pair of functions f,g∈ℱ, then ℱ is normal in D. This result generalizes the related theorem according to Xu et al. and Qi et al., respectively. There is a gap in the proofs of Lemma 3 by Wang (2012) and Theorem 1 by Zhang (2008), respectively. They did not consider the case of f(z) being zerofree. We will fill the gap in this paper.


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