讨论具有无穷时滞中立型泛函微分方程 d/dt(x(t)-∫-∞^0g(s,x(t+x))ds)=A(t,x(t))x(t)+f(t,xt) 的周期解问题,利用重合度理论中的延拓定理得到了周期解的存在性和唯一性条件;特别地,当g(s,x)≡0,A(t,x)=A(t)时,给出了存在唯一稳定周期解的条件。
Discuss the periodic solutions of the following neutral functional differential equa- tion with infinite delay d/dt(x(t)-∫-∞^0g(s,x(t+x))ds)=A(t,x(t))x(t)+f(t,xt) Some results on the existence and uniqueness of periodic solutions are obtained by using continuation theorem in coincidence degree. Especially, when g(s, x) =- 0 and A(t, x) = A(t), the conditions which guarantee the existence of the unique and stable periodic solution are derived.