Observational constraints on dark energy with a fast varying equation of state

Antonio De Felice*, Savvas Nesseris, Shinji Tsujikawa

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)


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.

Original languageEnglish
Article number029
JournalJournal of Cosmology and Astroparticle Physics
Issue number5
Publication statusPublished - 2012 May
Externally publishedYes


  • dark energy theory
  • supernova type Ia - standard candles

ASJC Scopus subject areas

  • Astronomy and Astrophysics


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