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On meromorphic solutions of functional-differential equations

Published online by Cambridge University Press:  10 February 2022

Feng Lü*
Affiliation:
College of Science, China University of Petroleum, Qingdao, Shandong266580, P.R. China (lvfeng18@gmail.com)

Abstract

We consider meromorphic solutions of functional-differential equations

\[ f^{(k)}(z)=a(f^{n}\circ g)(z)+bf(z)+c, \]
where $n,\,~k$ are two positive integers. Firstly, using an elementary method, we describe the forms of $f$ and $g$ when $f$ is rational and $a(\neq 0)$, $b$, $c$ are constants. In addition, by employing Nevanlinna theory, we show that $g$ must be linear when $f$ is transcendental and $a(\neq 0)$, $b$, $c$ are polynomials in $\mathbb {C}$.

Type
Research Article
Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press on Behalf of The Edinburgh Mathematical Society

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