Constraining the dark-energy equation of state with cosmological data

Understand

Recently, the observed equation of state for dark energy appears to favor values below $-1$.

• The tendency implies that the nature of dark energy may be quite different from that of the cosmological constant.
• In view of the adjustment on the equation of state keeps decreasing, the introduction of the phantom energy seems inevitable.
• By employing observational constraints from supernovae and from the acoustic scale in which the accuracy of the data has become extraordinary, we apply a phenomenological scenario to be acquainted with the evolution of our universe.