Acta mathematica scientia,Series A ›› 2017, Vol. 37 ›› Issue (1): 7-17.

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Normality Criteria of Meromorphic Functions with Zero Numbers

Wang Qiong1, Chen Wei2, Yuan Wenjun3, Tian Honggen1   

  1. 1. School of Mathematics Science, Xinjiang Normal University, Urumqi 830054;
    2. Department of Mathematics, Shandong University, Jinan 250100;
    3. School of Mathematics and Information Sciences, Guangzhou University, Guangzhou 510006
  • Received:2016-06-22 Revised:2016-12-02 Online:2017-02-26 Published:2017-02-26
  • Supported by:

    Supported by the NSFC (11461070, 11271090), the Nature Science Foundation of Guangdong Province (S2012010010121, 2015A030313346) and Innovation Projects (XJGRI2015106) of Xinjiang Province

Abstract:

This paper considers normality criteria for a family of meromorphic functions concerning zero numbers. Let F be a family of meromorphic functions defined in a domain D, all of whose zeros and poles have multiplicity at least k and k+1 respectively, let m, n and k be three positive integers satisfying nm+2, and a(≠0), b be two finite constants. If for each function fF, f(k)-afn-b has at most m distinct zeros in D, then F is normal in D. Our results improve theorem 1 by Deng et al.[18] and generalize the related theorems of Ye et al.[16], Zhang et al.[22] and Chen et al.[19]. Meanwhile, some examples are given to show the sharpness of our results.

Key words: Meromorphic function, Zero numbers, Normal criterion

CLC Number: 

  • O174.52
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