Speaker
Description
We present a complete analysis of the observational constraints and cosmological implications of our Bound Dark Energy (BDE) model aimed to explain the late-time cosmic acceleration of the universe. BDE is derived from particle physics and corresponds to the lightest meson field $\phi$ dynamically formed at low energies due to the strong gauge coupling constant. The evolution of BDE is determined by the scalar potential $V(\phi)=\Lambda_c^{4+2/3}\phi^{-2/3}$ arising from non-perturbative effects at a condensation scale $\Lambda_c$ and scale factor $a_c$, related each other by $a_c\Lambda_c/\mathrm{eV}=1.0934\times 10^{-4}$. We present the full background and perturbation evolution at a linear level. Using current observational data, we obtain the constraints $a_c=(2.48 \pm 0.02)\times10^{-6}$ and $\Lambda_c=(44.09 \pm 0.28) \textrm{ eV}$, which is in complete agreement with our theoretical prediction $\Lambda_c^{th}=34^{+16}_{-11}\textrm{ eV}$. The bounds of the EoS $w$, the DE density and the expansion rate are $w_\mathrm{BDE 0}=-0.929\pm 0.007$, $\Omega_\mathrm{BDE0}=0.696\pm0.007$ and $H_0=67.82\pm 0.05$ km s$^{-1}$Mpc. Even though the constraints on the Planck base parameters are consistent at 1$\sigma$ level between BDE and the concordance $\Lambda$CDM model, BDE improves the likelihood ratio by 2.1 of BAO measurements with respect to $\Lambda$CDM and has an equivalent fit SNIa and CMB data. We present the constraints on the different cosmological parameters, and particularly we show the tension between BDE and $\Lambda$CDM in the BAO distance ratio $r_\mathrm{BAO}$ vs $H_\mathrm{0}$ and the growth index $\gamma$ at different redshifts, as well as the DM density at present time $\Omega_ch^2$ vs $H_0$. These results allow us to discriminate between these two models.
