利用鞍点定理讨论了一类非自治二阶Hamilton系统:(t)+Au(t)+ΔF(t,u(t))=0,a.e.t∈(0,2π),u(0)-u(2π)=.u(0)-u.(2π)=0周期解的存在性,其中A是N×N实对称矩阵,A具有形如k2的特征值,非线性项ΔF(t,u(t))是线性增长的.
By saddle point theorem,the existence of periodic solution for a class of nonautomons second order system as follows:(t)+Au(t)+ΔF(t,u(t))=0,a.e.t∈(0,2π),u(0)-u(2π)=(0)-(2π)=0is studied.The symmetric matric A has eigenvalue k2,ΔF(t,u(t)) satisfies linear condition.