Dark Energy and Dark Matter in a Model of an Axion Coupled to a Non-Abelian Gauge Field

TL;DR

This paper proposes a cosmological model where an axion-like field coupled to a non-Abelian gauge field can simultaneously explain dark energy and dark matter, with dark energy dominance ending in the future as gauge field dark matter takes over.

Contribution

It introduces a novel model coupling a pseudo-scalar to a non-Abelian gauge field, unifying dark energy and dark matter explanations with specific cosmological dynamics.

Findings

Radial fluctuations act as dark matter.

Phase of the scalar field drives dark energy.

Dark energy dominance is temporary, replaced by gauge field dark matter.

Abstract

We study cosmological field configurations (solutions) in a model in which the pseudo-scalar phase of a complex field couples to the Pontryagin density of a massive non-abelian gauge field, in analogy to how the Peccei-Quinn axion field couples to the $SU(3)$-color gauge field of QCD. Assuming that the self-interaction potential of the complex scalar field has the typical {\it Mexican hat} form, we find that the radial fluctuations of this field can act as {\it Dark Matter}, while its phase may give rise to tracking {\it Dark Energy}. In our model, Dark-Energy domination will, however, not continue for ever. A new component of dark matter, namely the one originating from the gauge field, will dominate in the future.