Non-Perturbative Yang-Mills Condensate as Dark Energy

Understand

Models based on Yang-Mills condensate (YMC) have been advocated in the literature and claimed to be successful candidates to explain dark energy.

• Several instantiations of this simple idea have been considered, the most promising of which are reviewed here.
• Nevertheless, results previously attained heavily relied on the perturbative approach to the analysis of the effective Yang-Mills action, which is only adequate in the asymptotically-free limit, and were extended into a regime, the infrared limit, in which confinement is expected.
• We show that if a minimum of the effective Lagrangian in $\theta \!=\! - F_{\, \, \mu \nu}^a \, F^{a \mu \nu}/2$ exists, a YMC forms that drives the Universe toward an accelerated de Sitter phase.