Figueiredo, Giovany M.Pimenta, Marcos T. O. [UNESP]2022-04-292022-04-292013-01-01Bulletin of the Belgian Mathematical Society - Simon Stevin, v. 20, n. 3, p. 519-534, 2013.1370-1444http://hdl.handle.net/11449/227615We consider the fourth-order problem {ε4△2u + V(x)u = f(u) +γ |U|2..-2u inRN u ∈ H 2(RN), where ε > 0, N ≥ 5, V is a positive continuous potential, is a function with subcritical growth and γ ∈ {0,1}. We relate the number of solutions with the topology of the set where V attain its minimum values. We consider the subcritical case γ = 0 and the critical case γ = 1. In the proofs we apply Ljusternik-Schnirelmann theory.519-534engBiharmonic equationsNontrivial solutionsVariational methodsArtigo10.36045/bbms/13783145132-s2.0-84896359069