arXiv Analytics

Sign in

arXiv:1401.5615 [astro-ph.CO]AbstractReferencesReviewsResources

Investigating the Possibility of a Turning Point in the Dark Energy Equation of State

Yazhou Hu, Miao Li, Xiao-Dong Li, Zhenhui Zhang

Published 2014-01-22, updated 2014-08-05Version 3

We investigate a second order $parabolic$ parametrization, $w(a)=w_t+w_a(a_t-a)^2$, which is a direct characterization of a possible $turning$ in $w$. The cosmological consequence of this parametrization is explored by using the observational data of the SNLS3 type Ia supernovae sample, the CMB measurements from WMAP9 and Planck, the Hubble parameter measurement from HST, and the baryon acoustic oscillation (BAO) measurements from 6dFGS, BOSS DR11 and improved WiggleZ. We found the existence of a turning point in $w$ at $a\sim0.7$ is favored at 1$\sigma$ CL. In the epoch $0.55< a< 0.9$, $w<-1$ is favored at 1$\sigma$ CL, and this significance increases near $a=0.8$, reaching a 2$\sigma$ CL. The parabolic parametrization achieve equivalent performance to the $\Lambda$CDM and Chevallier-Polarski-Linder (CPL) models when the Akaike information criterion was used to assess them. Our analysis shows the value of considering high order parametrizations when studying the cosmological constraints on $w$.

Comments: 8 pages, 2 figures, 3 tables
Journal: SCIENCE CHINA Physics, Mechanics & Astronomy, 2014, 57 (8): 1607-1612
Categories: astro-ph.CO
Related articles: Most relevant | Search more
arXiv:0911.3198 [astro-ph.CO] (Published 2009-11-17, updated 2010-01-18)
The Dark Energy Equation of State using Alternative High-z Cosmic Tracers
arXiv:0905.2738 [astro-ph.CO] (Published 2009-05-17, updated 2009-10-23)
Constraints on the Phase Plane of the Dark Energy Equation of State
arXiv:1112.1693 [astro-ph.CO] (Published 2011-12-07)
Fables of reconstruction: controlling bias in the dark energy equation of state