From confinement to dark energy

TL;DR

This paper explores how long wavelength modes in QCD and cosmology could contribute to dark energy, potentially driving the universe towards de Sitter expansion, with implications for the infrared behavior of QCD vacuum energy.

Contribution

It proposes a novel connection between QCD infrared effects and cosmological dark energy, analyzing the impact of long wavelength modes on vacuum energy in a cosmological context.

Findings

Long wavelength modes enhance the QCD vacuum energy.

Residual energy density may drive de Sitter expansion.

Lattice studies constrain the parameter d.

Abstract

The infrared divergence of the self-energy of a color charge is due to an enhancement of the long wavelength modes of the color Coulomb potential field. There are also long wavelength contributions to the QCD vacuum energy that are similarly enhanced. Vacuum modes of Hubble scale wavelengths may be affected in a cosmological setting and this can lead to a residual positive energy density of the form $H^d\Lambda_{\rm QCD}^{4-d}$. Lattice studies constrain $d$. If the dark energy takes this form then the universe is driven towards de Sitter expansion, and we briefly study this cosmology when $d$ is just slightly above unity.