数学物理学报

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二阶微分方程解的零点分布

1吴昭君;2田宏根;3吴佳   

  1. (1.咸宁学院数学系 湖北 咸宁 437100; 2.新疆师范大学数学系 乌鲁木齐 830054; 3.咸宁职业技术学院基础部 湖北 咸宁 437100)
  • 收稿日期:2007-06-30 修回日期:2008-10-21 出版日期:2009-02-25 发布日期:2009-02-25
  • 通讯作者: 吴昭君
  • 基金资助:
    国家自然科学基金(10471048)和湖北省教育厅青年研究项目资助.

On the Distribution of Zeros of Solutions of Second Order Differential Equations

1Wu Zhaojun; 2Tian Honggen; 3Wu Jia   

  1. (1.Department of Mathematics, Xianning College, Hubei Xianning 437100;
    2.Department of Mathematics, Xingjiang Normal University, Wulumuqi 830054;
    3.Department of Basic, Xianning Technology College, Hubei Xianning 437100)

  • Received:2007-06-30 Revised:2008-10-21 Online:2009-02-25 Published:2009-02-25
  • Contact: Wu Zhaojun

摘要:

应用角域Nevanlinna理论和Ahlfors覆盖曲面理论, 研究了二阶微分方程f’’+A(z)f=0的解的零点分布. 证明了在复平面上至少存在一条半直线, 使得二阶微分方程解在该直线上的零点的径向收敛指数为无穷. 用新的方法证明了伍胜健在文献[5]中的一个定理.

关键词: 零点收敛指数, 复振荡, 超级, Borel方向.

Abstract:

In this paper, we investigate the distribution of zeros of solutions of second order differential equations f’’+A(z)f=0, where A(z) is an entire function of finite order. By using the Nevanlinna’s characteristic function and Ahlfors-Shimizu’s characteristic function on an angular domain, we established the existence of some ray which has the property that near which the exponent of convergence of the zero-sequence is infinite. Furthermore, by using a new method, we give a different proof of the Theorem 2 which has been given by Wu Shengjian in [5].

Key words: The exponent of convergence of the zero-sequence, Complex oscillation, Hyper order, Borel direction.

中图分类号: 

  • 34M20