CPT Violation and Decoherence in Quantum Gravity

TL;DR

This paper reviews potential CPT-violation signals caused by quantum decoherence in quantum gravity, focusing on experimental probes like cosmic neutrinos and meson experiments, and discusses specific models predicting observable effects.

Contribution

It provides a comprehensive overview of CPT-violation tests in quantum gravity, emphasizing unique signatures in meson entanglement and semi-microscopic estimates within string-inspired models.

Findings

Potential CPT-violation effects could modify EPR correlations in mesons.

Cosmic neutrino observations may reveal decoherence signatures.

String-inspired models estimate observable CPT-violation effects.

Abstract

In this brief review I discuss ways and tests of CPT-Violation in the context of quantum gravity theories with space-time foam vacua, which entail quantum decoherence of matter propagating in such backgrounds. I cover a wide variety of sensitive probes, ranging from cosmic neutrinos to meson factories. I pay particular emphasis on associating the latter with specific, probably unique ("smoking-gun"), effects of this type of CPT Violation, related to a modification of Einstein-Podolsky-Rosen (EPR) correlations in the entangled states of the relevant neutral mesons. I also present some semi-microscopic estimates of these latter effects, in the context of a specific string-inspired model of space-time foam ("D-particle foam").