on the fu c ˘ ik spectrum for the p-laplacian with robin boundary condition

 −δpu = a(u⁺)^p−1 − b(u⁻)^p−1 in ω,

|∇u|^p−2 ∂u/∂ν= −β|u|^p−2u on ∂ω,

where β ≥ 0. if β = 0, it reduces to the fu˘cik spectrum of the negative neumann p-laplacian. the existence of a first nontrivial curve c of this spectrum is shown and we prove some properties of this curve, e.g., c is lipschitz continuous, decreasing and has a certain asymptotic behavior. a variational characterization of the second eigenvalue λ₂ of the robin eigenvalue problem involving the p-laplacian is also obtained.