Bound dark energy: Particle origin of dark energy with DESI BAO and DES supernova data

Abstract: The recent findings from the Dark Energy Spectroscopic Instrument (DESI) indicate a preference for dynamical dark energy at a significance level above $2.5 \sigma$, with baryon acoustic oscillation (BAO) combined with cosmic microwave background (CMB) data and Type Ia supernovae (SNe) data, favoring a time dependent equation of state $w(z)$ rather than the cosmological constant ($w = -1$). We introduce the Bound Dark Energy (BDE) model, in which dark energy arises from the lightest meson field $\phi$ in a dark SU(3) gauge group, developing dynamically through non perturbative interactions. Governed by an inverse power law potential $V(\phi) = \Lambda_c^{4+2/3}\phi^{-2/3}$, BDE features no dark energy free parameters: one less than $\Lambda$CDM ($\Lambda$) and three less than the $ w_{0}w_{a} $CDM ($ w_{0}, w_{a},\Lambda $) models. By integrating DESI BAO measurements, CMB data and Dark Energy Survey SN Ia distance data collected during the fifth year, BDE demonstrates a reduction of $42$ and $37$ percent in the reduced $\chi^{2}_{BAO}$ as well as lower AIC and BIC values compared to the $w_{0}w_{a}$CDM and $\Lambda$CDM models, respectively, while maintaining a comparable fit for both type Ia supernovae and the cosmic microwave background data. Although the ($w_{0},w_{a}$) contour in BDE is 10,000 times smaller than that found in the $w_{0}w_{a}$CDM model, the BDE model suggests a dynamical dark energy scenario with precise values of $w_{0}=$-0.9301 $\pm$ 0.0004 and $w_{a}=$ -0.8085 $\pm$ 0.0053 while providing a consistency on the six Planck and derived parameters at the 1$\sigma$ level between BDE, $\Lambda$CDM and $w_{0}w_{a}$CDM models. The critical parameters condensation energy scale $\Lambda_{c} = 43.806 \pm 0.190$ eV and epoch $a_{c} = (2.497 \pm 0.011) \times 10^{-6}$ are consistent with predictions from high energy physics.