TY - JOUR
T1 - Observational constraints on dark energy with a fast varying equation of state
AU - De Felice, Antonio
AU - Nesseris, Savvas
AU - Tsujikawa, Shinji
PY - 2012/5
Y1 - 2012/5
N2 - We place observational constraints on models with the late-time cosmic acceleration based on a number of parametrizations allowing fast transitions for the equation of state of dark energy. In addition to the model of Linder and Huterer where the dark energy equation of state w monotonically grows or decreases in time, we propose two new parametrizations in which w has an extremum. We carry out the likelihood analysis with the three parametrizations by using the observational data of supernovae type Ia, cosmic microwave background, and baryon acoustic oscillations. Although the transient cosmic acceleration models with fast transitions can give rise to the total chi square smaller than that in the Λ-Cold-Dark-Matter (ΛCDM) model, these models are not favored over ΛCDM when one uses the Akaike information criterion which penalizes the extra degrees of freedom present in the parametrizations.
AB - We place observational constraints on models with the late-time cosmic acceleration based on a number of parametrizations allowing fast transitions for the equation of state of dark energy. In addition to the model of Linder and Huterer where the dark energy equation of state w monotonically grows or decreases in time, we propose two new parametrizations in which w has an extremum. We carry out the likelihood analysis with the three parametrizations by using the observational data of supernovae type Ia, cosmic microwave background, and baryon acoustic oscillations. Although the transient cosmic acceleration models with fast transitions can give rise to the total chi square smaller than that in the Λ-Cold-Dark-Matter (ΛCDM) model, these models are not favored over ΛCDM when one uses the Akaike information criterion which penalizes the extra degrees of freedom present in the parametrizations.
KW - dark energy theory
KW - supernova type Ia - standard candles
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U2 - 10.1088/1475-7516/2012/05/029
DO - 10.1088/1475-7516/2012/05/029
M3 - Article
AN - SCOPUS:84861806484
VL - 2012
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
SN - 1475-7516
IS - 5
M1 - 029
ER -