Existence results for singular φ-Laplacian problems in presence of lower and upper solutions

Abstract

This paper is devoted to the study of the existence of solutions to singular φ-Laplacian problems, coupled with nonlinear functional boundary value conditions, in presence of a pair of well-ordered lower and upper solutions. The main result ensures the existence of solutions for a functional problem. It improves previous ones due to Bereanu and Mawhin related to non-homogeneous Dirichlet equations. Some of the used arguments follow the line of some previous papers devoted to regular φ-Laplacian operators.