CPT Violation and Decoherence in Quantum Gravity

TL;DR

This paper reviews theoretical motivations and phenomenological implications of CPT violation in quantum gravity, emphasizing decoherence due to space-time foam as a plausible scenario that could explain neutrino anomalies.

Contribution

It provides a pedagogical overview of CPT violation models in quantum gravity, focusing on decoherence effects from space-time foam and their potential to explain neutrino experimental anomalies.

Findings

Decoherence from space-time foam can induce CPT violation in quantum gravity.

CPT violating decoherence can explain neutrino anomalies like LSND without new neutrino types.

The scenario aligns with current experimental data on neutrinos.

Abstract

In these lectures I review, in as much pedagogical way as possible, various theoretical ideas and motivation for violation of CPT invariance in some models of Quantum Gravity, and discuss the relevant phenomenology. Since the subject is vast, I pay particular emphasis on the CPT Violating decoherence scenario for quantum gravity, due to space-time foam. In my opinion this seems to be the most likely scenario to be realised in Nature, should quantum gravity be responsible for the violation of this symmetry. In this context, I also discuss how the CPT Violating decoherence scenario can explain experimental ``anomalies'' in neutrino data, such as LSND results, in agreement with the rest of the presently available data, without enlarging the neutrino sector.