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Finite and infinite order of growth of solutions to linear differential equations near a singular point

Samir Cherief, Saada Hamouda (2021)

Mathematica Bohemica

In this paper, we investigate the growth of solutions of a certain class of linear differential equation where the coefficients are analytic functions in the closed complex plane except at a finite singular point. For that, we will use the value distribution theory of meromorphic functions developed by Rolf Nevanlinna with adapted definitions.

Finiteness of meromorphic functions on an annulus sharing four values regardless of multiplicity

Duc Quang Si, An Hai Tran (2020)

Mathematica Bohemica

This paper deals with the finiteness problem of meromorphic funtions on an annulus sharing four values regardless of multiplicity. We prove that if three admissible meromorphic functions f 1 , f 2 , f 3 on an annulus 𝔸 ( R 0 ) share four distinct values regardless of multiplicity and have the complete identity set of positive counting function, then f 1 = f 2 or f 2 = f 3 or f 3 = f 1 . This result deduces that there are at most two admissible meromorphic functions on an annulus sharing a value with multiplicity truncated to level 2 and...

Fixed points of meromorphic functions and of their differences and shifts

Zong-Xuan Chen (2013)

Annales Polonici Mathematici

Let f(z) be a finite order transcendental meromorphic function such that λ(1/f(z)) < σ(f(z)), and let c ∈ ℂ∖0 be a constant such that f(z+c) ≢ f(z) + c. We mainly prove that m a x τ ( f ( z ) ) , τ ( Δ c f ( z ) ) = m a x τ ( f ( z ) ) , τ ( f ( z + c ) ) = m a x τ ( Δ c f ( z ) ) , τ ( f ( z + c ) ) = σ ( f ( z ) ) , where τ(g(z)) denotes the exponent of convergence of fixed points of the meromorphic function g(z), and σ(g(z)) denotes the order of growth of g(z).

Further investigation “On an open problem of Zhang and Xu”

Sujoy Majumder (2018)

Mathematica Bohemica

The purpose of the paper is to study the uniqueness of meromorphic functions sharing a nonzero polynomial. The result of the paper improves and generalizes the recent results due to X. B. Zhang and J. F. Xu (2011). We also solve an open problem posed in the last section of X. B. Zhang and J. F. Xu (2011).

Further investigations on a question of Zhang and Lü

Abhijit Banerjee, Bikash Chakraborty (2015)

Annales Universitatis Paedagogicae Cracoviensis. Studia Mathematica

In the paper based on the question of Zhang and Lü [15], we present one theorem which will improve and extend results of Banerjee-Majumder [2] and a recent result of Li-Huang [9].

Generalization of uniqueness and value sharing of meromorphic functions concerning differential polynomials

Harina P. Waghamore, Ramya Maligi (2020)

Communications in Mathematics

The motivation of this paper is to study the uniqueness problems of meromorphic functions concerning differential polynomials that share a small function. The results of the paper improve and generalize the recent results due to Fengrong Zhang and Linlin Wu [13]. We also solve an open problem as posed in the last section of [13].

Generalizations on the results of Cao and Zhang

Sujoy Majumder, Rajib Mandal (2022)

Mathematica Bohemica

We establish some uniqueness results for meromorphic functions when two nonlinear differential polynomials P ( f ) i = 1 k ( f ( i ) ) n i and P ( g ) i = 1 k ( g ( i ) ) n i share a nonzero polynomial with certain degree and our results improve and generalize some recent results in Y.-H. Cao, X.-B. Zhang (2012). Also we exhibit two examples to show that the conditions used in the results are sharp.

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