Positive solutions for second order functional differential equations
The existence of positive solutions to second-order equations of the form \(u''+ a(t) f(u)= 0\) is studied under integral boundary conditions. These functional conditions generalize multipoint boundary conditions. The nonlinearity \(f\) is considered separately to be sublinear or superlinear. The proof is based on a fixed-point theorem in cones and a verification of related analytical inequalities.
scientific article; zbMATH DE number 1693114