Dark Energy and QCD Ghost

TL;DR

This paper demonstrates that the QCD ghost in a realistic cosmological model can produce dark energy with the correct magnitude, potentially explaining the universe's accelerated expansion.

Contribution

It advances previous simplified models by incorporating all components of the QCD ghost, showing it can generate the observed dark energy magnitude.

Findings

QCD ghost contributes to dark energy proportional to Hubble parameter and QCD scale

Dark energy magnitude matches observed value (~(3×10^{-3} eV)^4)

Realistic modeling confirms QCD ghost's role in cosmic acceleration

Abstract

It has been suggested that the dark energy that explains the observed accelerating expansion of the universe may arise due to the contribution to the vacuum energy of the QCD ghost in a time-dependent background. The argument uses a four-dimensional simplified model. In this paper, we put the discussion in more realistic model keeping all components of the QCD vector ghost and show that indeed QCD ghost produces dark energy proportional to the Hubble parameter $H\Lambda_{QCD}^3$ ($\Lambda_{QCD}$ is the QCD mass scale) which has the right magnitude $\sim (3\times 10^{-3}$ eV)$^4$.