Locating peaks of a Schrödinger equation with sign-changing nonlinearity

In this paper, we study the concentration phenomenon of a positive ground state solution of a nonlinear Schrödinger equation on RNRN. The coefficient of the nonlinearity of the equation changes sign. We prove that the solution has a maximum point at x0∈Ω+={x∈RN:Q(x)>0}x0∈Ω+={x∈RN:Q(x)>0} where the energy attains its minimum.