Abstract
In this paper, the second-quantized theory of free particles and antiparticles, with any spin and with internal or symmetry, is developed. All spins and both statistics are treated in a uniform way in terms of well-defined complete sets of functions that are orthonormal with respect to a Lorentz-invariant positive-definite inner product. Explicit formulas for field operators of energy, momentum, etc., are given, including three-vector, four-vector, and tensor operators for polarization. It is shown that causal space densities of physical quantities exist when the correct spin-statistics connection is used. The field operators for systems self-conjugate under , , and are treated and self-conjugate multiplets of are set up.
DOI:https://doi.org/10.1103/RevModPhys.40.508
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