Speaker
Description
We present a physically motivated dark-energy (DE) model rooted in the topological structure ofthe Quantum ChromoDynamic (QCD) vacuum. In this framework, which is coined as QCD-DE, the dark energy arises from the differencebetween the vacuum energy of an expanding FLRW universe and Minkowski spacetime, induced by tunnelling transitions between the QCD topological sectors. There are no any new degrees of freedom here as entire framework is based on standard model physics. The Equation of State $w_{DE}(z)$ in QCD-DE model depends on time and crosses the line $w_{DE}=-1$ at $z\sim 1$ which is consistent with recent DESI results. We argue that the vacuum energy and the de Sitter phase in QCD-DE emerges dynamically with the scale $\rho_{DE}\approx H\Lambda_{QCD}^3 \approx (10^{-3} eV)^4$, which is amazingly close to the observed value without introducing any new parameters.
We consider pairwise and triplet combinations of CMB, BAO and SNIa datasets for $\Lambda\mathrm{CDM}$, $w_0w_a\mathrm{CDM}$ and the QCD-DE models. We argue that the QCD-DE model is preferred by Bayesian evidence in comparison with $\Lambda\mathrm{CDM}$, $w_0w_a\mathrm{CDM}$ models (this part of the work is still in progress, to be posted soon).