滞后中立型高维周期系统周期解的存在性

THE EXISTENCE OF PERIODIC SOLUTIONS TO HIGHER DIMENSIONAL PERIODIC SYSTEM OF NEUTRAL TYPE WITH DELAY

对滞后中立型高维周期系统ｘ′（ｔ）＝Ａ（ｔ，ｘ（ｔ））ｘ（ｔ）＋ｆ（ｔ，ｘ（ｔ－ｒ１））＋Ｂ（ｔ）ｘ′（ｔ－ｒ２），利用不动点方法。

In this paper, higher dimensional periodic systems of neutral type with delay of the form: x′(t)=A(t,x(t))x(t)+f(t,x(t-r 1 ))+B(t)x′(t-r 2) are considered. Using fixed point method, some sufficient conditions to guarantee the existence of periodic solution for the systems are obtained .