Guseinov, GSYaslan, IMathematics2024-07-052024-07-0520040022-247X10.1016/j.jmaa.2003.10.0132-s2.0-1342263792https://doi.org/10.1016/j.jmaa.2003.10.013https://hdl.handle.net/20.500.14411/1104Yaslan, İsmail/0000-0003-3502-198XIn this paper, we consider boundary value problems for nonlinear differential equations on the semi-axis (0, infinity) and also on the whole axis (-infinity, infinity), 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 L-2(0, infinity) and L-2(-infinity, infinity), and include boundary conditions at infinity. The existence and uniqueness results for solutions of the considered boundary value problems are established. (C) 2003 Elsevier Inc. All rights reserved.eninfo:eu-repo/semantics/closedAccessWeyl limit-circle casecompletely continuous operatorfixed point theoremsArticleQ2Q22902620638WOS:00018885440002027