GROWTH AND OSCILLATION OF DIFFERENTIAL POLYNOMIALS GENERATED BY COMPLEX DIFFERENTIAL EQUATIONS (original) (raw)

Growth of solutions and oscillation of differential polynomials generated by some complex linear differential equations

Hokkaido Mathematical Journal, 2010

This paper is devoted to studying the growth and the oscillation of solutions of the second order non-homogeneous linear differential equation f + A 1 (z)e P (z) f + A 0 (z)e Q(z) f = F, where P (z), Q(z) are nonconstant polynomials such that deg P = deg Q = n and A j (z) (≡ 0) (j = 0, 1), F ≡ 0 are entire functions with ρ(A j) < n (j = 0, 1). We also investigate the relationship between small functions and differential polynomials g f (z) = d 2 f + d 1 f + d 0 f , where d 0 (z), d 1 (z), d 2 (z) are entire functions that are not all equal to zero with ρ(d j) < n (j = 0, 1, 2) generated by solutions of the above equation.

On the growth and the zeros of solutions of higher order linear differential equations with meromorphic coefficients

Publications de l'Institut Mathematique, 2015

We investigate the growth of meromorphic solutions of homogeneous and nonhomogeneous higher order linear differential equations f (k) + k−1 j=1 A j f (j) + A 0 f = 0 (k 2), f (k) + k−1 j=1 A j f (j) + A 0 f = A k (k 2), where A j (z) (j = 0, 1,. .. , k) are meromorphic functions with finite order. Under some conditions on the coefficients, we show that all meromorphic solutions f ≡ 0 of the above equations have an infinite order and infinite lower order. Furthermore, we give some estimates of their hyper-order, exponent and hyper-exponent of convergence of distinct zeros. We improve the results due to Kwon; Chen and Yang; Belaïdi; Chen; Shen and Xu.