一类具有偏差变元的三阶泛函微分方程周期解的存在唯一性

摘要

利用重合度理论，研究一类具有偏差变元的三阶时滞泛函微分方程x′″（t）＋∑2i=[aix（1）＋bix（i）（t-τi）]＋cx（t）＋g1（x（t））＋g2（x（t-τ（t）））=e（t）的T-周期解问题，获得了上述方程弘周期解存在和唯一性的若干新结果．%In this paper, by means of the theory of coincident degree, T-periodic solution of a type of third order functional differential equation with delays x′″（t）＋∑2i=[aix（1）＋bix（i）（t-τi）]＋cx（t）＋g1（x（t））＋g2（x（t-τ（t）））=e（t） is studied. Several new results about the existance and uniqueness of T-periodic solution of above equation are obtained.