Nonlinear eigenvalue problems for a biharmonic operator in Orlicz-Sobolev spaces

Abstract

In this paper, we introduce a new higher-order Laplacian operator in the framework of Orlicz-Sobolev spaces, the biharmonic g-Laplacian $$\hat{I}{”}_g^{2}u:=\hat{I}”\left(\frac{g(|\hat{I}”u|)}{|\hat{I}”u|}\hat{I}”u\right),$$ where $g=G^{\prime }$, with $G$ an N-function. This operator is a generalization of the so called bi-harmonic Laplacian $\hat{I}{”}^2$. Here, we also established basic functional properties of $\hat{I}{”}_g^2$, which can be applied to existence results. Afterwards, we study the eigenvalues of $\hat{I}{”}_g^2$, which depend on normalisation conditions, due to the lack of homogeneity of the operator. Finally, we study different nonlinear eigenvalue problems associated to $\hat{I}{”}_g^2$ and we show regimes where the corresponding spectrum concentrate at $0$, $\infty$ or coincide with $(0,\infty )$.