A multiplicity theorem for anisotropic Robin equations
Nikolaos S. Papageorgiou, Patrick Winkert · Rendiconti Lincei Matematica e Applicazioni · 2022
In this paper, we consider an anisotropic Robin problem driven by the p(x) -Laplacian and a superlinear reaction. Applying variational tools along with truncation and comparison techniques as well as critical groups, we prove that the problem has at least five nontrivial smooth solutions to be ordered and with sign information: two positive, two negative, and the fifth nodal.