Parametric nonlinear resonant Robin problemsPapageorgiou, Nikolaos S. (Avtor) Rǎdulescu, Vicenţiu (Avtor) Repovš, Dušan (Avtor) indefinite and unbounded potentialcritical groupsmultiple solutionsnonlinear regularityresonanceRobin boundary conditionstrong comparisontruncationWe consider a nonlinear Robin problem driven by the ▫$p$▫-Laplacian. In the reaction we have the competing effects of two nonlinearities. One term is parametric, strictly ▫$(p-1)$▫-sublinear and the other one is ▫$(p-1)$▫-linear and resonant at any nonprincipal variational eigenvalue. Using variational tools from the critical theory (critical groups), we show that for all big values of the parameter ▫$\lambda$▫ the problem has at least five nontrivial smooth solutions.20192019-12-04 07:19:13Članek v reviji113103sl