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This article is cited in 3 scientific papers (total in 3 papers)
Uniqueness theorems for meromorphic functions on annuli
A. Rathod B.L.D.E.Association's S.B. Arts and K.C.P. Science College, Department of Mathematics, SMT. Bangaramma Sajjan Campus, Solapur Road, Vijayapura-586103, Karnataka, India
Abstract:
In this paper, we discuss the uniqueness problems of meromorphic functions on annuli. We prove a general theorem on the uniqueness of meromorphic functions on annuli. An analogue of a famous Nevanlinna's five-value theorem is proposed. The main result in this paper is an analog of a result on the plane $\mathbb{C}$ obtained by H.S. Gopalkrishna and Subhas S. Bhoosnurmath for an annuli. That is, let $f_{1}(z)$ and $f_{2}(z)$ be two transcendental meromorphic functions on the annulus $\mathbb{A}=\left\{z:\frac{1}{R_{0}}<|z|<R_{0}\right\}$, where $1<R_{0}\leq +\infty.$ Let $a_{j}$, $j=1,2,\ldots,q)$, be $q$ distinct complex numbers in $\overline{\mathbb{C}}$, and $k_{j}$, $j=1,2,\ldots,q$ be positive integers or $\infty$ satisfying \begin{equation*} k_{1}\geq k_{2}\geq \ldots \geq k_{q}. \end{equation*} If \begin{equation*} \overline{E}_{k_{j})}(a_{j},f_{1})=\overline{E}_{k_{j})}(a_{j},f_{2}), j=1,2,\ldots,q, \end{equation*} and \begin{equation*} \sum_{j=2}^{q}\frac{k_{j}}{k_{j}+1}-\frac{k_{1}}{k_{1}+1}>2, \end{equation*} then $f_{1}(z)\equiv f_{2}(z).$
Keywords:
Nevanlinna theory, meromorphic functions, annuli.
Received: 04.06.2019
Citation:
A. Rathod, “Uniqueness theorems for meromorphic functions on annuli”, Ufa Math. J., 12:1 (2020), 114–120
Linking options:
https://www.mathnet.ru/eng/ufa507https://doi.org/10.13108/2020-12-1-114 https://www.mathnet.ru/eng/ufa/v12/i1/p115
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