Existence of periodic solutions for second-order neutral differential equations.
The higher order neutral functional differential equation is considered under the following conditions: , , is strictly increasing in , for , , , and is nonnegative on and nondecreasing in . A necessary and sufficient condition is derived for the existence of certain positive solutions of (1).
In this paper we study the existence of classical solutions for a class of abstract neutral integro-differential equation with unbounded delay. A concrete application to partial neutral integro-differential equations is considered.