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Some normality criteria of function families concerning shared values
Author(s) -
Yuan Wenjun,
Li Zhirong,
Lin Jianming
Publication year - 2012
Publication title -
mathematical methods in the applied sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.719
H-Index - 65
eISSN - 1099-1476
pISSN - 0170-4214
DOI - 10.1002/mma.2639
Subject(s) - meromorphic function , normality , mathematics , normal family , multiplicity (mathematics) , zero (linguistics) , function (biology) , creating shared value , combinatorics , pure mathematics , value (mathematics) , discrete mathematics , mathematical analysis , statistics , law , evolutionary biology , biology , linguistics , philosophy , corporate social responsibility , political science
In this paper, we study the normality of families of meromorphic functions concerning shared values. We consider mainly whether a family meromorphic functions F is normal in D , if (i) for every pair of functions f and g in F , f ( k ) − af n and g ( k ) − ag n share the value b , and (ii) f has no zero of multiplicity less than k in D for every function f ∈ F , where a and b are two finite complex numbers such that a ≠ 0, n ≥ k + 3 and k ≥ 2 are two positive integers. An example shows that the condition (ii) in our results is best possible. Copyright © 2012 John Wiley & Sons, Ltd.