Constraining the Dark Universe

We combine complementary datasets to constrain dark energy. Using standard Big Bang Nucleosynthesis and the observed abundances of primordial nuclides to put constraints on ${\mathrm{\Omega }}_Q$ at temperatures near $T\sim 1MeV$, we find the strong constraint ${\mathrm{\Omega }}_Q(MeV)<0.045$ at $2\sigma$ c.l… Under the assumption of flatness, using results from Cosmic Microwave Background (CMB) anisotropy measurements, high redshift supernovae (SN-Ia) observations and data from local cluster abundances we put a new constraint on the equation of state parameter $w_Q<-0.85$ at 68% c.l…