Robin problems with a general potential and a superlinear reaction
arXiv:1706.03560 · doi:10.1016/j.jde.2017.04.032
Abstract
We consider semilinear Robin problems driven by the negative Laplacian plus an indefinite potential and with a superlinear reaction term which need not satisfy the Ambrosetti-Rabinowitz condition. We prove existence and multiplicity theorems (producing also an infinity of smooth solutions) using variational tools, truncation and perturbation techniques and Morse theory (critical groups).