Existence, nonexistence and multiplicity of positive solutions for singular boundary value problems involving $\varphi$-Laplacian

Abstract: In this paper, we establish the results on the existence, nonexistence and multiplicity of positive solutions to singular boundary value problems involving $\varphi$-Laplacian. Our approach is based on the fixed point index theory. The interesting point is that a result for the existence of three positive solutions is given.