Abstract:

By employing the coincidence degree, a kind of higher order differential equations with delay  and the equation x⁽ⁿ⁾(t)+h(x´(t))+f(x(t))x´(t)+g(x(t-τ(t)))=p(t) are studied. Some new results on the existence of  T(T>0) periodic solutions are obtained, which generalizes the known results.

Key words: higher order differential equation; periodic solution; coincidence degree