Eigenvalues of the negative (p,q)-Laplacian under a Steklov-like boundary condition

ABSTRACTIn this paper, we consider in a bounded domain Ω⊂RN with smooth boundary an eigenvalue problem for the negative (p,q)-Laplacian with a Steklov-type boundary condition, where p∈(1,∞), q∈(2,∞) and p≠q. A full description of the set of eigenvalues of this problem is provided, thus essentially extending a recent result by Abreu and Madeira related to the (p,2)-Laplacian.