James S. W. Wong

Linearization of second-order nonlinear oscillation theorems

The problem of oscillation of super- and sublinear Emden-Fowler equations is studied. Established are a number of oscillation theorems involving comparison with related linear equations. Recent results on linear oscillation can thus be used to obtain interesting oscillation criteria for nonlinear equations. 25 references.

Two point boundary value problems for nonlinear functional differential equations

This paper is concerned with the existence of solutions of two point boundary value problems for functional differential equations. Specifically, we consider /(f) = L(t, yt) +f(t, y,), Mya + Nyb = <A, where M and N are linear operators on C[0, K\. Growth conditions are imposed on /to obtain the existence of solutions. This result is then specialized to the case where L(t, yt) = A(t)y(t), that is, when the reduced linear equation is an ordinary rather than a functional differential equation. Several examples are discussed to illustrate the results.