Abstract
We introduce a new parametrization for the dark energy, led by the same idea to the linear expansion of the equation of state in scale factor a and in redshift z, which diverges neither in the past nor future and contains the same number of degrees of freedom with the former two. We present constraints of the cosmological parameters using the most updated baryon acoustic oscillation (BAO) measurements along with cosmic microwave background (CMB) data and a recent reanalysis of Type Ia supernova (SN) data. This new parametrization allowed us to carry out successive observational analyses by decreasing its degrees of freedom systematically until ending up with a dynamical dark energy model that has the same number of parameters with ΛCDM . We found that the dark energy source with a dynamical equation of state parameter equal -2/3 at the early universe and -1 today fits the data slightly better than Λ.
| Original language | English |
|---|---|
| Article number | 049 |
| Journal | Journal of Cosmology and Astroparticle Physics |
| Volume | 2015 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 1 Jun 2015 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2015 IOP Publishing Ltd and Sissa Medialab srl .
Keywords
- dark energy experiments
- dark energy theory