Three solutions for a nonlinear equation involving p-triharmonic operators

The existence of at least three weak solutions for a nonlinear elliptic Navier boundary value problem involving the p-triharmonic operator is investigated. The main tools used for obtaining our results are two critical points theorems established in [B. Ricceri, A three critical points theorem revisited, Nonlinear Anal. 9 (2009), 3084-3089] and [G. Bonanno, S.A. Marano, On the structure of the critical set of non-differentiable functionals with a weak compactness condition, Appl. Anal. 89 (2010), 1-10]. © 2021 Journal of Nonlinear Functional Analysis