Multiple positive solutions of fourth-order four-point boundary-value problems with changing sign coefficient.
In this paper, using a fixed point theorem on a convex cone, we consider the existence of positive solutions to the multipoint one-dimensional -Laplacian boundary value problem with impulsive effects, and obtain multiplicity results for positive solutions.
We study the existence and multiplicity of positive solutions of the nonlinear fourth order problem ⎧ in (0,1), ⎨ ⎩u(0) = a ≥ 0, u’(0) = a’ ≥ 0, u(1) = b ≥ 0, u(1) = -b’ ≤ 0 The methods employed are upper and lower solutions and degree theory arguments.
We study the existence of positive solutions to second order nonlinear differential equations with Neumann boundary conditions. The proof relies on a fixed point theorem in cones, and the positivity of Green's function plays a crucial role in our study.