Lakshmikantham, V. Some problems in integrodifferential equations of Volterra type. (English) Zbl 0598.45015 J. Integral Equations 10, Suppl., 137-146 (1985). Using the method of upper and lower solutions, monotone iterative techniques and a contraction mapping theorem for operators whose domain and range are different Banach spaces [see S. R. Bernfeld, the author and Y. M. Reddy, Appl. Anal. 6, 271-280 (1977; Zbl 0375.47027)] the author proves two existence theorems for the system (1) \(u'=f(t,u,Tu)\), \(u(0)=u(2\pi)\), where \((Tu)(t)=\int^{t}_{0}K(t,s)u(s)ds\). Furthermore, the extension of the Lyapunov method for the equation (1) is discussed. A general comparison theorem which enables to consider a unified stability theory for this equation is proved. Reviewer: M.TvrdĂ˝ Cited in 13 Documents MSC: 45J05 Integro-ordinary differential equations 45N05 Abstract integral equations, integral equations in abstract spaces Keywords:periodic boundary value problem; upper and lower solutions; monotone iterative techniques; Banach spaces; existence; Lyapunov method; comparison; stability Citations:Zbl 0375.47027 PDF BibTeX XML Cite \textit{V. Lakshmikantham}, J. Integral Equations 10, 137--146 (1985; Zbl 0598.45015)