Bulletin of the Korean Mathematical Society (대한수학회보)

Korean Mathematical Society (대한수학회)
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A RESULT ON AN OPEN PROBLEM OF LÜ, LI AND YANG

  • Received : 2020.08.09
  • Accepted : 2021.03.12
  • Published : 2021.07.31
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Abstract

In this paper we deal with the open problem posed by Lü, Li and Yang [10]. In fact, we prove the following result: Let f(z) be a transcendental meromorphic function of finite order having finitely many poles, c1, c2, …, cn ∈ ℂ\{0} and k, n ∈ ℕ. Suppose fn(z), f(z+c1)f(z+c2) ⋯ f(z+cn) share 0 CM and fn(z)-Q1(z), (f(z+c1)f(z+c2) ⋯ f(z+cn))(k) - Q2(z) share (0, 1), where Q1(z) and Q2(z) are non-zero polynomials. If n ≥ k+1, then $(f(z+c_1)f(z+c_2)\;{\cdots}\;f(z+c_n))^{(k)}\;{\equiv}\;{\frac{Q_2(z)}{Q_1(z)}}f^n(z)$. Furthermore, if Q1(z) ≡ Q2(z), then $f(z)=c\;e^{\frac{\lambda}{n}z}$, where c, λ ∈ ℂ \ {0} such that eλ(c1+c2+⋯+cn) = 1 and λk = 1. Also we exhibit some examples to show that the conditions of our result are the best possible.

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References

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