Dark Matter and Global Symmetries

TL;DR

This paper explores how quantum gravity considerations challenge the stability of dark matter models relying on global symmetries, deriving bounds from astrophysical data that exclude many dark matter candidates across a wide mass spectrum.

Contribution

It provides the first comprehensive, model-independent limits on dark matter decay from global symmetry breaking, applying these bounds to various theoretical models and mass ranges.

Findings

Global symmetry breaking constrains dark matter lifetime.

Many fermionic, vector, and scalar dark matter candidates are ruled out.

Bounds exclude dark matter in the keV-TeV mass range.

Abstract

General considerations in general relativity and quantum mechanics are known to potentially rule out continuous global symmetries in the context of any consistent theory of quantum gravity. Assuming the validity of such considerations, we derive stringent bounds from gamma-ray, X-ray, cosmic-ray, neutrino, and CMB data on models that invoke global symmetries to stabilize the dark matter particle. We compute up-to-date, robust model-independent limits on the dark matter lifetime for a variety of Planck-scale suppressed dimension-five effective operators. We then specialize our analysis and apply our bounds to specific models including the Two-Higgs-Doublet, Left-Right, Singlet Fermionic, Zee-Babu, 3-3-1 and Radiative See-Saw models. {Assuming that (i) global symmetries are broken at the Planck scale, that (ii) the non-renormalizable operators mediating dark matter decay have $O(1)$ couplings, that (iii) the dark matter is a singlet field, and that (iv) the dark matter density distribution is well described by a NFW profile}, we are able to rule out fermionic, vector, and scalar dark matter candidates across a broad mass range (keV-TeV), including the WIMP regime.