Further investigate on periodic solutions of pth order delayed NDEs

摘要

This paper points out that Fourier series theory and inequality techniques used by the present authors in an earlier publication proves a stronger version on existence and uniqueness of periodic solutions for a class of pth order neutral differential equations (NDEs) with some delays:∑i=0paix(i)(t)+∑j=1m∑i=0pujix(i)(t−hj)=f(t).Thus some previous results are contained, extended and improved.