Boundary value problems for second order nonlinear differential equations on infinite intervals

Abstract

In this paper, we consider boundary value problems for nonlinear differential equations on the semi-axis (0,?) and also on the whole axis (-?,?), under the assumption that the left-hand side being a second order linear differential expression belongs to the Weyl limit-circle case. The boundary value problems are considered in the Hilbert spaces L2(0,?) and L2(-?,?), and include boundary conditions at infinity. The existence and uniqueness results for solutions of the considered boundary value problems are established.