Commutation Relations of Interacting Spinor Fields

Abstract

It is shown that the requirement that the Hamiltonian density commute with itself on a spacelike surface precludes the possibility that three or more different spinor fields, coupled to one another in Yukawa-type interactions, commute with each other. If the Hamiltonian contains only two such fields, however, they may be assumed either to commute or to anticommute without violating this requirement.