Global Topology and Local Violation of Discrete Symmetries

TL;DR

This paper explores cosmological models with extended gauge groups that include anti-unitary transformations, analyzing conditions under which discrete symmetries like P, C, and CP can be violated or must be preserved.

Contribution

It constructs models incorporating anti-unitary transformations in gauge groups and analyzes their implications for discrete symmetry violations in cosmology.

Findings

Models obeying Einstein causality cannot violate P, C, and CP.

A model violating charge superselection rule is possible.

Fundamental laws likely preserve discrete symmetries or are non-causal.

Abstract

Cosmological models that are locally consistent with general relativity and the standard model in which an object transported around the universe undergoes P, C and CP transformations, are constructed. This leads to generalization of the gauge fields that describe electro-weak and strong interactions by enlarging the gauge groups to include anti-unitary transformations. Gedanken experiments show that if all interactions obey Einstein causality then P, C and CP cannot be violated in these models. But another model, which would violate charge superselection rule even for an isolated system, is allowed. It is suggested that the fundamental physical laws must have these discrete symmetries which are broken spontaneously, or they must be non causal.