A new existence theory for single and multiple positive periodic solutions to volterra integro-differential equations with impulse effects

AbstractThis paper presents a new existence theory for single and multiple positive periodic solutions to a kind of nonautonomous Volterra integro-differential equations with impulse effects. Existence is established by using Krasnoselskii fixed-point theorem in cones. This paper extends some previous results and reports some new results about impulsive differential equatio