Published online by Cambridge University Press: 20 January 2009
The purpose of this paper is to discuss non-linear boundary value problems for elliptic systems of the type
where Ak is a second order uniformly elliptic operator and is such that the problem
has a one-dimensional space of solutions that is generated by a non-negative function. The boundary ∂G is supposed to be smooth and the functions gk, 1≦k≦m are defined on Ḡ×Rm and are continuously differentiate (usually, Bk represents Dirichlet or Neumann conditions and is the first eigenvalue associated with Ak and such boundary conditions).