Existence of positive solutions for a kind of periodic boundary value problem at resonance
Institute of Mathematics, University of Rzeszów, Rejtana 16 A, Rzeszów, 35-959, Poland
Boundary Value Problems 2013, 2013:19 doi:10.1186/1687-2770-2013-19Published: 11 February 2013
In the paper we provide sufficient conditions for the existence of positive solutions for some second-order differential equation subject to periodic boundary conditions. Our method employs a Leggett-Williams norm-type theorem for coincidences due to O’Regan and Zima. Two examples are given to illustrate the main result of the paper.