Year: 2007
Type: article
Abstract: The new 182 gold supernova Ia data, the baryon acoustic oscillation measurement and the shift parameter determined from the Sloan Digital Sky Survey, and the three-year Wilkinson Microwave Anisotropy Probe data are combined to reconstruct the dark energy equation of state parameter $w(z)$ and the deceleration parameter $q(z)$. We find that the strongest evidence of acceleration happens around the redshift $z\ensuremath{\sim}0.2$ and the stringent constraints on $w(z)$ lie in the redshift range $z\ensuremath{\sim}0.2--0.5$. At the sweet spot, $\ensuremath{-}1.2<w(z)<\ensuremath{-}0.6$ for the dark energy parametrization $w(z)={w}_{0}+{w}_{a}z/(1+z{)}^{2}$ at the $3\ensuremath{\sigma}$ confidence level. The transition redshift ${z}_{t}$ when the Universe underwent the transition from deceleration to acceleration is derived to be ${z}_{t}={0.36}_{\ensuremath{-}0.08}^{+0.23}$. The combined data is also applied to find out the geometry of the Universe, and we find that at the $3\ensuremath{\sigma}$ confidence level, $|{\ensuremath{\Omega}}_{k}|\ensuremath{\lesssim}0.05$ for the simple one-parameter dark energy model, and $\ensuremath{-}0.064<{\ensuremath{\Omega}}_{k}<0.028$ for the $\ensuremath{\Lambda}\mathrm{CDM}$ model.
Authors: Yungui Gong, Anzhong Wang
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: 暗能量及其热力学研究, 暗能量的研究
OpenAlex ID: W2594496772