PERTURBATION RESULTS OF SECOND ORDER LINEAR DIFFERENTIAL EQUATIONS WITH PERIODIC COEFFICIENTS

Two perturbation results on the linear differential function f" ∏(z)A(z)f = 0 areobtained, where ∏(z) and A(z) are periodic entire functions with period 2πi and σe(∏) ＜σe(A).     

SOME OSCILLATION THEOREMS OF HIGHER ORDER NON－HOMOGENEOUS LINEAR DIFFERENTIAL EQUATIONS WITH TRANSCENDENTAL MEROMORPIC COEFFICIENTS

ＳＯＭＥＯＳＣＩＬＬＡＴＩＯＮＴＨＥＯＲＥＭＳＯＦＨＩＧＨＥＲＯＲＤＥＲＮＯＮ－ＨＯＭＯＧＥＮＥＯＵＳＬＩＮＥＡＲＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＷＩＴＨＴＲＡＮＳＣＥＮＤＥＮＴＡＬＭＥＲＯＭＯＲＰＩＣＣＯＥＦＦＩＣＩＥＮＴＳ￥ＣｈｅｎＺｏ...     

ON THE ITERATED ORDER OF MEROMORPHIC SOLUTIONS OF HIGHER ORDER LINEAR DIFFERENTIAL EQUATIONS

In this paper, we investigate complex homogeneous and non-homogeneous higher order linear differential equations with meromorphic coefficients. We obtain several results concerning the iterated order of meromorphic solutions, and the iterated convergence exponent of the zeros of meromorphic solutions.     

A NOTE ON THE COMPLEX OSCILLATION OF NONHOMOGENEOUS LINEAR DIFFERENTIAL EQUATIONS WITH TRANSCENDENTAL ENTIRE COEFFICIENTS

ＡＮＯＴＥＯＮＴＨＥＣＯＭＰＬＥＸＯＳＣＩＬＬＡＴＩＯＮＯＦＮＯＮＨＯＭＯＧＥＮＥＯＵＳＬＩＮＥＡＲＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＷＩＴＨＴＲＡＮＳＣＥＮＤＥＮＴＡＬＥＮＴＩＲＥＣＯＥＦＦＩＣＩＥＮＴＳＧａｏＳｈｉａｎ；＆ＷａｎｇＳｈｅｎ...     

OSCILLATIONS OF SECOND ORDER DIFFERENTIAL EQUATIONS WITH IMPULSES

１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｐａｐｅｒ，ｗｅｃｏｎｓｉｄｅｒｔｈｅｓｅｃｏｎｄ－ｏｒｄｅｒｄｉｆｅｒｅｎｔｉａｌｅｑｕａｔｉｏｎｓｗｉｔｈｉｍｐｕｌｓｅｓａｓ（ｒ（ｔ）ｘ′）′＋ｆ（ｔ，ｘ）＝０，ｔ≥ｔ０，ｔ≠０，ｋ＝１，２，…，ｘ（ｔ＋ｋ）...     

THE COMPLEX OSCILLATION OF NON－HOMOGENEOUS LINEAR DIFFERENTIAL EQUATIONS WITH INFINITE ORDER ENTIRE COEFFICIENTS

ＴＨＥＣＯＭＰＬＥＸＯＳＣＩＬＬＡＴＩＯＮＯＦＮＯＮ－ＨＯＭＯＧＥＮＥＯＵＳＬＩＮＥＡＲＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＷＩＴＨＩＮＦＩＮＩＴＥＯＲＤＥＲＥＮＴＩＲＥＣＯＥＦＦＩＣＩＥＮＴＳ￥ＬｉＸｉａｎｙｕ（李贤瑜）（ＪｉａｎｇｘｉＮｏｒ...     

THE ESTIMATION OF CHARACTERISTIC EXPONENTS FOR A CLASS OF SECOND ORDER LINEAR DIFFERENTIAL EQUATION WITH PERIODIC COEFFICIENTS

In this paper we shall give a simple and easy method to estimate the characteristic exponents for a class of second order linear different equation with periodic coefficient which frequently occurs in application.     

PERTURBATIONS OF ZEROS OF SOLUTIONS TO SECOND ORDER DIFFERENTIAL EQUATIONS WITH POLYNOMIAL COEFFICIENTS＊

Let P(z) and (P)(z) be polynomials of the same degree. We consider the equations u" =P(z)u and (u)" =(P)(z)(u) (z ∈ C) whose solutions are u(z) and (u)(z),respectively.Let zk(u) and zk((u)),k =1,2,…,be...     

ON THE HYPER-ORDER OF MEROMORPHIC SOLUTIONS OF LINEAR DIFFERENTIAL EQUATIONS

In this paper the order and the hyper-order of the solutions of higher-order homoge-neous linear differential equations is investigated.     

OSCILLATION OF HIGHER ORDER NEUTRAL DIFFERENTIAL EQUATIONS WITH POSITIVE AND NEGATIVE COEFFICIENTS

ＯＳＣＩＬＬＡＴＩＯＮＯＦＨＩＧＨＥＲＯＲＤＥＲＮＥＵＴＲＡＬＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳＷＩＴＨＰＯＳＩＴＩＶＥＡＮＤＮＥＧＡＴＩＶＥＣＯＥＦＦＩＣＩＥＮＴＳＬｉＷａｎｔｏｎｇ（李万同）（ＺｈａｎｇｙｅＴｅａｃｈｅｒｓ＇Ｃｏｌｌｅｇｅ...     

关于超越亚纯系数微分方程亚纯解的零点

本文研究了非齐次线性微分方程的复振荡问题，其中，D0，D1，…，D(k-1)，是超越亚纯函数．当存在某个Ds（1≤s≤k-1）比其它Dj（j≠s）有较快增长的意义下起支配作用时，得到了微分方程（I）亚纯解的零点收敛指数的精确估计式．     

二阶线性微分方程亚纯解的不动点与超级

本文研究了以亚纯函数为系数的二阶线性微分方程的解及其一阶和二阶导数的不动点及超级问题，得到：二阶线性微分方程亚纯解及其一阶和二阶导数的不动点性质，由于受到微分方程的限制，与一般亚纯函数的不动点性质相比是十分有趣的，事实上，它们与解的增长性密切相关。     

关于慢增长系数非齐次线性微分方程亚纯解的级和零点

本文研究了非齐次线性微分方程ｆ（ｋ） ＋ Ｄｋ－ １ｆ（ｋ－ １） ＋ …＋ Ｄ０ｆ ＝ Ｆ （１）的复振荡问题．其中Ｄ０,…,Ｄｋ－ １是增长级小于１／２的亚纯函数,Ｆ０是有限级亚纯函数．当存在某个ＤＳ（０≤ｓ≤ｋ－ １）比其它Ｄｊ（ｊ≠ｓ）有较快增长的意义下起支配作用时,得到了微分方程（Ⅰ）的一定条件下亚纯解的级和零点的估计式．     

二阶代数微分方程亚纯解的增长性估计

本文研究了代数微分方程亚纯解的增长级.运用正规族理论,给出了某类二阶代数微分方程亚纯解的增长级的一个估计,该估计依赖于方程的有理函数系数.推广了2001年廖良文与杨重骏的一个结果.     

圆内零级亚纯函数的充满圆及应用

本文研究了圆内零级亚纯函数的充满圆序列,获得了在关于型函数的Borel点附近存在充满圆序列,从而得到了Hayman点的存在性.