Positive solutions of elliptic equations with nonlinear boundary conditions Original Research Article

This paper deals with the nonlinear elliptic equation View the MathML source−Δu+u=f(x,u) in a bounded smooth domain Ω⊂RNΩ⊂RN with a nonlinear boundary value condition. The existence results are obtained by the sub–supersolution method and the Mountain Pass Lemma. And nonexistence is also considered.