Iannacci, R.; Nkashama, M. N. On periodic solutions of forced second order differential equations with a deviating argument. (English) Zbl 0568.34056 Ordinary and partial differential equations, Proc. 8th Conf., Dundee/Scotl. 1984, Lect. Notes Math. 1151, 224-232 (1985). [For the entire collection see Zbl 0564.00005.] Using classical Leray-Schauder’s techniques and coincidence degree, we prove the existence of periodic solutions for forced second order delay- differential equations under nonuniform nonresonance conditions with respect to the spectrum of the linear ordinary differential equation with periodicity conditions. Our approach allows us to derive some uniqueness result. Cited in 4 Documents MSC: 34K99 Functional-differential equations (including equations with delayed, advanced or state-dependent argument) 34C25 Periodic solutions to ordinary differential equations 34B30 Special ordinary differential equations (Mathieu, Hill, Bessel, etc.) 47H10 Fixed-point theorems 47J05 Equations involving nonlinear operators (general) Keywords:Leray-Schauder’s techniques; coincidence degree; forced second order delay-differential equations; nonuniform nonresonance conditions Citations:Zbl 0564.00005 PDF BibTeX XML OpenURL