Abstract

Time-symmetric relativity, based on the Zisman-Stueckelberg-Feynman interpretation, includes reference frames moving backward in ordinary time and extends symmetry to the full Lorentz group O(1,3) with four-inversion. The article formulates time-symmetric quantum field theory as a theory of many-particle systems with positive state norms, no zero-point vacuum energy, causal propagators, and the usual diagram technique. Accounting for gravity at the Planck scale provides gravitational self-regularization of loop diagrams, finite perturbation series in the Standard Model and quantum gravity, and finite chiral-anomaly contributions that cancel in the Standard Model.