In this paper, we study existence of nontrivial solutions to the elliptic equationNontrivial solutions are obtained in the case in which the nonlinearities have linear growth. That is, for some c > 0, | f (x, u)| ≤ c|u| for x ∈ and u ∈ R, and −cI m ≤ ∇ 2 u V (x, u) ≤ cI m for x ∈ and u ∈ R m , where I m is the m × m identity matrix. In sharp contrast to the existing results in the literature, we do not make any assumptions at infinity on the asymptotic behaviors of the nonlinearity f and ∇ u V .
Mathematics Subject Classification (2000)35J55 · 35J65 · 58E05 Z.