Research Article
Xiaodong Zhao and Lin Chen
Abstract
In this paper, by the Mountain Pass Theory and Ekeland’s variational principle, we consider the existence and multiplicity of nontrivial solutions for the nonhomogeneous semilinear elliptic system    −∆u + u = α α+β f(x)|u| α−2u|v| β + l1(x), x ∈ Ω, −∆v + v = β α+β f(x)|u| α|v| β−2v + l2(x), x ∈ Ω, ∂u ∂n = λg(x)|u| q−2u, ∂v ∂n = µh(x)|v| q−2 v, x ∈ ∂Ω, where Ω is a bounded domain in R N with smooth boundary, α > 1, β > 1 satisfying 2 < α+β < 2 ∗ (2∗ = 2N N−2 if N ≥ 3, 2 ∗ = ∞ if N = 2), 1 < q < 2, the pair of parameters (λ, µ) ∈ R 2 \ {(0, 0)}