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arXiv 0909.0596astro-ph.COgr-qchep-th
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暗能量动力学演化的观测约束

Observational constraint on dynamical evolution of dark energy

Yungui Gong, Rong-Gen Cai, Yun Chen, Zong-Hong Zhu

摘要:

利用本构超新星、重子声学振荡、宇宙微波背景辐射和哈勃参数数据分析了暗能量的演化特性。将不同的重子声学振荡数据与Constitution超新星数据相结合,拟合到Chevallier-Polarski-Linder模型中,得到了不同的结果。我们发现,差异源于不同的值的$Ω_{m0}$。我们还适合观测数据的模型独立的分段常数参数化。选取了边界分别为$z=0.22$、0.53、0.85和1.8的四个红移面元,对暗能量的状态方程参数$w(z)$进行了分段常数参数化。我们没有发现进化$w(z)$的显著证据。通过引入哈勃参数,使高红移状态方程参数的约束条件提高了70%。讨论了与超新星距离模有关的讨厌参数的边缘化问题。

英文摘要:

We use the Constitution supernova, the baryon acoustic oscillation, the cosmic microwave background, and the Hubble parameter data to analyze the evolution property of dark energy. We obtain different results when we fit different baryon acoustic oscillation data combined with the Constitution supernova data to the Chevallier-Polarski-Linder model. We find that the difference stems from the different values of $Ω_{m0}$. We also fit the observational data to the model independent piecewise constant parametrization. Four redshift bins with boundaries at $z=0.22$, 0.53, 0.85 and 1.8 were chosen for the piecewise constant parametrization of the equation of state parameter $w(z)$ of dark energy. We find no significant evidence for evolving $w(z)$. With the addition of the Hubble parameter, the constraint on the equation of state parameter at high redshift isimproved by 70%. The marginalization of the nuisance parameter connected to the supernova distance modulus is discussed.

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