Existence of periodic solutions for first-order delay differential equations via critical point theory

Existence and uniqueness of solutions for neutral periodic integro-differential equations with infinite delay

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Periodic solutions of fourth-order delay differential equation

In this paper the periodic solutions of fourth order delay differential equation of the form $ddddot{x}(t)+adddot{x}(t)+f(ddot{x}(t-tau(t)))+g(dot{x}(t-tau(t)))+h({x}(t-tau(t)))=p(t)$  is investigated. Some new positive periodic criteria are given.  

Existence of solutions of first-order differential equations via a fixed point theorem for discontinuous operators

*Correspondence: [email protected] Departamento de Análise Matemática, Facultade de Matemáticas, Universidade de Santiago de Compostela, Campus Sur, Santiago de Compostela, 15782, Spain Abstract We use a recent Schauder-type result for discontinuous operators in order to look for solutions for first-order differential equations subject to initial functional conditions. We show how this abstr...

existence and uniqueness of solutions for neutral periodic integro-differential equations with infinite delay

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ON TE EXISTENCE OF PERIODIC SOLUTION FOR CERTAIN NONLINEAR THIRD ORDER DIFFERENTIAL EQUATIONS