北京大学学报(自然科学版)

一类具有正负系数的中立型方程的振动性

张晓声,王铎   

  1. 北京大学数学科学学院,北京,100871
  • 收稿日期:2000-12-06 出版日期:2002-01-20 发布日期:2002-01-20

Oscillation on Neutral Differential Equations with Positive and Negative Coefficients

ZHANG Xiaosheng,WANG Duo   

  1. School of Mathematical Sciences, Peking University, Beijing, 100871
  • Received:2000-12-06 Online:2002-01-20 Published:2002-01-20

摘要: 给出中立型方程d/dt[x(t)-R(t)x(t-r)]+P(t)x(t-τ)-Q(t)x(t-δ)=0振动的充分条件。这里R(t)+∫tt-τ+δQ(u)du-1可以是变号的,并且不要求∫t0s[P(s)-Q(s-τ+δ)]∫s[P(u)-Q(u-τ+δ)]duds=∞.

关键词: 中立型方程, 振动性

Abstract: Sufficient conditions for the oscillation of the equation d/dt[x(t)-R(t)x(t-r)]+P(t)x(t-τ)-Q(t)x(t-δ)=0 are obtained whereR(t)+∫t t-τ+δQ(u)du-1 is allowed to oscillates and the condition ∫t0s[P(s)-Q(s-τ+δ)]∫s[P(u)-Q(u-τ+δ)]duds=∞ is not necessary.

Key words: neutral equation, oscillation

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