In order to derive an expression for the four-spinor ω, the matrices α and β must be given in concrete form. The precise form that they take is representation-dependent. For the entirety of this article, the Dirac representation is used. In this representation, the matrices are α α → → = [ 0 σ σ → → σ σ → → 0 ] β β = [ I 0 0 − − I ]