On a problem in complex oscillation theory of periodic second order linear differential equations and some related perturbation results.
In this paper we discuss the growth of solutions of the higher order nonhomogeneous linear differential equation where , are complex constants that satisfy and
We study the hyper-order of analytic solutions of linear differential equations with analytic coefficients having the same order near a finite singular point. We improve previous results given by S. Cherief and S. Hamouda (2021). We also consider the nonhomogeneous linear differential equations.