In this paper,we examine semilinear Neumann problems which at $\pm\infty$ are resonant with respect to
two
successive eigenvalues (double resonance situation). Using
variational methods based on the critical point theory together
with Morse theory, we prove two multiplicity results. In the
first we obtain two nontrivial solutions and in the second
three, two of which have constant sign (one positive, the other
negative).
@article{1299766494,
author = {Filippakis, Michael E. and Papageorgiou, Nikolaos S.},
title = {Multiplicity of Solutions for Doubly Resonant Neumann Problems},
journal = {Bull. Belg. Math. Soc. Simon Stevin},
volume = {18},
number = {1},
year = {2011},
pages = { 135-156},
language = {en},
url = {http://dml.mathdoc.fr/item/1299766494}
}
Filippakis, Michael E.; Papageorgiou, Nikolaos S. Multiplicity of Solutions for Doubly Resonant Neumann Problems. Bull. Belg. Math. Soc. Simon Stevin, Tome 18 (2011) no. 1, pp. 135-156. http://gdmltest.u-ga.fr/item/1299766494/