Critical sets of nonlinear Sturm-Liouville operators of Ambrosetti-Prodi type

H. Bueno, C. Tomei

The critical set C of the operator F:H^2_D([0,pi]) -> L^2([0,pi]) defined by F(u)=-u''+f(u) is studied. Here X:=H^2_D([0,pi]) stands for the set of functions that satisfy the Diric…