Two meromorphic functions on annuli sharing some pairs of small functions or values

Abstract

In this paper, we prove that two admissible meromorphic functions on an annulus must be linked by a quasi-Möbius transformation if they share some pairs of small function with multiplicities truncated by 4. We also give the representation of Möbius transformation between two admissible meromorphic functions on an annulus if they share four pairs of values with multiplicities truncated by 4. In our results, the zeros with multiplicities more than a certain number are not needed to be counted if their multiplicities are bigger than a certain number.

Keywords

• meromorphic function
• small function
• quasi-möbius transformation
• nevanlinna theory