Periodic Solutions of the Second-Order Neutral Functional Differential Systems with Operator Varying in Time and Delays

Abstract

We study the existence of periodic solutions for second-order neutral functional differential systems with operator varying in time and delays. An interesting issue is that the coefficient matrix of the neutral difference operator is not a constant matrix, which contradicts the available literature data. Some properties of the neutral difference operator variable as a function of time and the results on the existence of periodic solutions of the second-order neutral functional differential systems are obtained. Moreover, numerical simulations are performed to illustrate the theoretical results.