Positive Ground State And Nodal Solution For Fractional Nonlinear Schr(?)dinger Equation With Indefinite Potential

We consider the following fractional nonlinear schr(?)dinger equation.where s?(0,1), N? 3,V is a sign changing potential and the nonlinearity f?C~1(R,R)is a subcritical and superlinear function.By combing variational techniques and the splitting Lemma we obtain a positive ground state solution and a nodal solution.