Full description of the eigenvalue set of the Steklov (p,q)-Laplacian

Abstract In this paper we consider in a bounded domain Ω ⊂ R N with smooth boundary an eigenvalue problem for the negative ( p , q ) -Laplacian with a Steklov-like boundary condition, where p , q ∈ ( 1 , ∞ ) , p ≠ q , including the open case p ∈ ( 1 , ∞ ) , q ∈ ( 1 , 2 ) , p ≠ q . A full description of the set of eigenvalues of this problem is provided. Our results complement those previously obtained by Abreu-Madeira [1] , Barbu-Morosanu [2] , Fărcăseanu-Mihăilescu-Stancu Dumitru [9] , Mihăilescu [16] , Mihăilescu-Morosanu [17] .