Recent Existence Results for Second-Order Singular Periodic Differential Equations
1 Department of Mathematics, College of Science, Hohai University, Nanjing 210098, China
2 Department of Mathematics, Pusan National University, Busan 609-735, South Korea
3 Departamento de Análisis Matemático, Facultad de Matemáticas, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
Boundary Value Problems 2009, 2009:540863 doi:10.1155/2009/540863Published: 8 June 2009
We present some recent existence results for second-order singular periodic differential equations. A nonlinear alternative principle of Leray-Schauder type, a well-known fixed point theorem in cones, and Schauder's fixed point theorem are used in the proof. The results shed some light on the differences between a strong singularity and a weak singularity.