Narrowing constraints with type Ia supernovae: converging on a cosmological constant
Narrowing constraints with type Ia supernovae: converging on a cosmological constant
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DOI：
10.1088/1475-7516/2007/09/004
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发表时间：
2007-06
影响因子：
6.4
通讯作者：
Scott T. Sullivan;A. Cooray;D. Holz
中科院分区：
文献类型：
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作者：
Scott T. Sullivan;A. Cooray;D. Holz
我们应用一个参数化无关的方法来拟合暗能量状态方程（EOS）。利用最新的Ia型超新星观测数据，结合宇宙微波背景辐射和重子声学振荡的结果，我们发现暗能量与宇宙学常数是一致的。我们通过对角化协方差矩阵建立了暗能量EOS演化的独立估计。我们发现了三个独立的约束条件，这三个约束条件合在一起意味着状态方程在红移范围01.2的68%置信水平下比-0.2更负，并且在今天滚到-1的值，以及“解冻”模型，其中EOS在高红移时接近-1，但在z<0.2时迅速演变到大于-0.85的值。最后，我们提出了一个参数化独立的品质因数（FOM），以帮助评估未来的调查约束暗能量的能力。虽然更常见的FOM假设一个特定的暗能量参数化的两个参数，我们建议一个binning方法来评估暗能量的限制与最小数量的假设。
We apply a parameterization-independent approach to fitting the dark energy equation-of-state (EOS). Utilizing the latest type Ia supernova data, combined with results from the cosmic microwave background and baryon acoustic oscillations, we find that the dark energy is consistent with a cosmological constant. We establish independent estimates of the evolution of the dark energy EOS by diagonalizing the covariance matrix. We find three independent constraints, which taken together imply that the equation of state is more negative than −0.2 at the 68% confidence level in the redshift range 01.2 and rolls to a value of −1 today, and ‘thawing’ models where the EOS is near −1 at high redshifts, but rapidly evolves to values greater than −0.85 at z<0.2. Finally, we propose a parameterization-independent figure of merit (FOM), to help assess the ability of future surveys to constrain dark energy. While the more common FOM presumes a specific dark energy parameterization with two parameters, we suggest a binning approach to evaluate dark energy constraints with a minimum number of assumptions.