Existence and Location Results for Fully Nonlinear Boundary Value Problem of nth-Order Nonlinear System

By appropriate bounding function pair and modified functions, using the theory of differential inequalities, this paper presents the existence and location criteria of solutions for the system of general nth-order differential equations with nonlinear boundary conditions. We give an example showing that the results are sharp. Our results extend many existing results

Uniqueness and existence for perturbed focal boundary value problems

AbstractAssuming a uniqueness assumption on the variational boundary value problems, uniqueness and existence is established for problems which generalize focal boundary value problems