“…The functional corresponding to problems (1.1) is It is well known operator -Δ has a sequence of eigenvalues satisfying 0 < 1 < 2 < ⋯ < → +∞. For general , ∈ 1, +∞ , (−∆ , −∆ ) has a smallest eigenvalue, i.e., the principle value, 1 , which is positive, isolated, simple (see [2]) and admit the following variational characterization…”