to annihilation and creation operators satisfying
[aj(p),a†k(p′)]+=δjkδ^3 (p−p′)The theory of non-relativistic electrons is something different than simply
two copies of a single fermionic field, since it describes spin^12 particles, not pairs
of spin 0 particles. In section 38.3.3 we will see how the groupE ̃(3) acts on the
theory, giving angular momentum observables corresponding to spin^12 rather
than two copies of spin 0.
37.6 For further reading
See the same references at the end of chapter 36 for more details about the ma-
terial of this one. A discussion of the physics described by the formalism of this
chapter can be found in most quantum field theory textbooks and in textbooks
dealing with the many-particle formalism and condensed matter theory. Two
textbooks that explicitly discuss the non-relativistic case are [35] and [45].