MULTIPLE SOLUTIONS FOR QUASILINEAR ELLIPTIC PROBLEMS WITH NONLINEAR BOUNDARY CONDITIONS

Using a recent result by Bonanno [2], we obtain a multiplicity result for the quasilinear elliptic problem -Delta(p)u + vertical bar u vertical bar(p-2)u = lambda f(u) in Omega, vertical bar del u vertical bar(p-2) partial derivative u/partial derivative v = mu g(u) on partial derivative Omega, where Omega is a bounded domain in R-N, N >= 3 with smooth boundary partial derivative Omega, partial derivative/partial derivative v is the outer unit normal derivative, the functions f, g are (p - 1)-sublinear at infinity (1 < p < N), lambda and mu are positive parameters.