Testing the nature of Dark Energy with Precision Cosmological constraints

Abstract

We present a Dark Energy (DE) model with a sound derivation as a natural extension of the Standard Model of particle physics with no free parameters and an excellent fit with current cosmological data improving by 21% the $\Lambda$CDM fit of the Baryon Acoustic Oscillations (BAO) measurements, specially designed to determine the dynamics of DE. DE corresponds to the lightest bound state scalar particle $\phi$ with a potential $V=\Lambda_c^{4+2/3}\phi^{-2/3}$ dynamically formed at the condensation energy scale $\Lambda_c$ and scale factor $a_c$. The value of $\Lambda_c$, the exponent $n=2/3$, and the initial conditions of $\phi$ are all derived quantities. We obtain an exact constraint $a_c\Lambda_c/\textrm{eV}=1.0939\times 10^{-4}$ and a theoretical prediction $\Lambda_c=34 ^{+16}_{-11} \textrm{ eV}$, consistent with the best fit $\Lambda_c=44.08\pm 0.27 \textrm{ eV}$. We test our model constraint on $a_c\Lambda_c$ by allowing $a_c$ and $\Lambda_c$ to vary independently and remarkably our prediction has a relative difference of only 0.2% with the best fit value. Unlike a cosmological constant $\Lambda$, our DE model predicts the amount of DE and leaves detectable cosmological imprints at different times and scales at a background and perturbation level.