%0 Journal Article
%T Resonance and Landesman-Lazer conditions for first order systems in R^2
%A Maurizio Garrione
%J Le Matematiche
%D 2011
%I University of Catania
%X The first part of the paper surveys the concept of resonance for T-periodic nonlinear problems. In the second part, some new results about existence conditions for nonlinear planar systems are presented. In particular, the Landesman-Lazer conditions are generalized to systems in R^2 where the nonlinearity interacts with two resonant Hamiltonians. Such results apply to second order equations, generalizing previous theorems by Fabry [4] (for the undamped case), and Frederickson-Lazer [9] (for the case with friction). The results have been obtained with A. Fonda, and have been published in [8].
%K Resonance
%K Landesman-Lazer conditions
%K Planar systems
%U http://www.dmi.unict.it/ojs/index.php/lematematiche/article/view/864