Partial sharing of a set of meromorphic functions and normality

Abstract

By using the idea of partial sharing of a set of meromorphic functions by a member of a family of meromorphic functions  and its kth derivative we obtain a normality criterion generalizing some of the earlier results on shared sets and normal families of  meromorphic functions. Further we prove a normality criterion which improves Marty’s theorem and its reverse counterpart.

Keywords

• Normal families,meromorphic function,partial sharing of sets,spherical derivative

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