On ground state solutions for superlinear Dirac equation

This article is concerned with the nonlinear Dirac equations −i∂tψ=icℏ∑k=13αk∂kψ−mc2βψ+Rψ(x,ψ)   in   ℝ3. Under suitable assumptions on the nonlinearity, we establish the existence of ground state solutions by the generalized Nehari manifold method developed recently by Szulkin and Weth.