We study the existence of positive solutions to second order nonlinear differential equations with Neumann boundary conditions. The proof relies on a fixed point theorem in cones, and the positivity of Green's function plays a crucial role in our study.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-am32-3-4, author = {Jifeng Chu and Daqing Jiang and Donal O'Regan and R. P. Agarwal}, title = {Multiplicity of positive solutions to second order differential equations with Neumann boundary conditions}, journal = {Applicationes Mathematicae}, volume = {32}, year = {2005}, pages = {293-303}, zbl = {1100.34017}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-am32-3-4} }
Jifeng Chu; Daqing Jiang; Donal O'Regan; R. P. Agarwal. Multiplicity of positive solutions to second order differential equations with Neumann boundary conditions. Applicationes Mathematicae, Tome 32 (2005) pp. 293-303. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-am32-3-4/