Sign-changing solutions for Schrödinger equations with indefinite supperlinear nonlinearities

In this paper, we obtain existence of ground state solutions and ground state sign-changing solutions for the following Schrödinger equation {−Δu+V(x)u=K(x)|u|p−2uin RNu→0as |x|→+∞, where N≥3N≥3, 2