A topological version of the Ambrosetti-Prodi theorem
Volume 64 / 1996
Annales Polonici Mathematici 64 (1996), 121-130
DOI: 10.4064/ap-64-2-121-130
Abstract
The existence of at least two solutions for nonlinear equations close to semilinear equations at resonance is obtained by the degree theory methods. The same equations have no solutions if one slightly changes the right-hand side. The abstract result is applied to boundary value problems with specific nonlinearities.
