Quantum Gravity Effects on Dark Matter and Gravitational Waves

TL;DR

This paper investigates how quantum gravity-induced symmetry breaking impacts dark matter stability and domain walls, proposing observational signatures in gravitational waves and CMB data, with a simple scalar field model illustrating these effects.

Contribution

It introduces a model linking quantum gravity effects to dark matter and domain wall phenomena, suggesting observational constraints via gravitational wave data.

Findings

Gravitational wave spectrum can constrain quantum gravity effects.

Quantum gravity effects can break discrete symmetries affecting dark matter.

Proposed model links symmetry breaking to observable signals.

Abstract

We explore how quantum gravity effects, manifested through the breaking of discrete symmetry responsible for both Dark Matter and Domain Walls, can have observational effects through CMB observations and gravitational waves. To illustrate the idea we consider a simple model with two scalar fields and two $\mathcal{Z}_2$ symmetries, one being responsible for Dark Matter stability, and the other spontaneously broken and responsible for Domain Walls, where both symmetries are assumed to be explicitly broken by quantum gravity effects. We show the recent gravitational wave spectrum observed by several pulsar timing array projects can help constrain such effects.