On a class fractional Schr\"odinger equations with indefinite potential   involving critical exponential growth
  It is established the existence and multiplicity of weak solutions for a class of nonlocal equations involving the fractional laplacian, nonlinearities with critical exponential growth and potentials this is which may change sign. The proofs of our existence results rely on minimization methods in combination with the mountain-pass theorem. 
Manass\'es de Souza and Yane Lisley Ara\'ujo
math.AP