Chinese Quarterly Journal of Mathematics ›› 2019, Vol. 34 ›› Issue (3): 221-231.doi: 10.13371/j.cnki.chin.q.j.m.2019.03.001

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Normality Criteria of Zero-free Meromorphic Functions

  

  1. School of Mathematics and Information Science, Guangzhou University School of Financial Mathematics and Statistics, Guangdong University of Finance
  • Received:2016-12-19 Online:2019-09-30 Published:2020-08-22
  • Contact: XIE Jia (1992-), femal, native of Meizhou, Guangdong, a Ph.D student of Guangzhou University, engages in complex analysis; DENG Bing-mao (1985-), male, native of Jieyang, Guangdong, a lecture of Guangdong University of Finance, Guangzhou University, engages in complex analysis.
  • Supported by:
    Supported by the NNSF of China(No.11701188)

Abstract: Let k be a positive integer,let h(z)■0 be a holomorphic functions in a domain D,and let F be a family of zero-free meromorphic functions in D,all of whose poles have order at least l.If,for each f∈P(f)(z)-h(z) has at most k+l-1 distinct zeros(ignoring multiplicity) in D,where P(f)(z)=f(k)(z)+a1(z)f((k-1)(z)+…+ak(z)f(z) is a differential polynomial of f and aj(z)(j=1,2,···,k) are holomorphic functions in D,then F is normal in D. 

Key words: Meromorphic Functions, Normality, Zero-free

CLC Number: