Ardjouni, Abdelouaheb; Djoudi, Ahcene Existence of positive periodic solutions for two kinds of nonlinear neutral differential equations with variable delay. (English) Zbl 1268.34127 Dyn. Contin. Discrete Impuls. Syst., Ser. A, Math. Anal. 20, No. 3, 357-366 (2013). Summary: We study the existence of positive periodic solutions for classes of nonlinear neutral differential equations with variable delay. The main tool employed here is Krasnosel’skii’s hybrid fixed point theorem dealing with a sum of two mappings, one is a contraction and the other is completely continuous. Cited in 4 Documents MSC: 34K13 Periodic solutions to functional-differential equations 34K40 Neutral functional-differential equations 47N20 Applications of operator theory to differential and integral equations Keywords:positive periodic solutions; nonlinear neutral differential equations; fixed point theorem PDFBibTeX XMLCite \textit{A. Ardjouni} and \textit{A. Djoudi}, Dyn. Contin. Discrete Impuls. Syst., Ser. A, Math. Anal. 20, No. 3, 357--366 (2013; Zbl 1268.34127) Full Text: Link