Extension of Wheeler-Feynman quantum theory to the relativistic domain. I. Scattering processes

The quantization of Wheeler-Feynman direct interparticle action electrodynamics is refined and extended to the relativistic domain, using the S-matrix technique developed previously. The analysis is effected on the exact expression for S, rather than the perturbation expansion. Source particles are treated as indistinguishable fermions with antiparticles. The response of the universe is incorporated in a general way, without allusion to specific absorber mechanisms. All the results of conventional QED emerge, provided one makes certain cosmological assumptions.