Distance Priors from Planck and Dark Energy Constraints from Current Data
Distance Priors from Planck and Dark Energy Constraints from Current Data
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DOI：
10.1103/physrevd.88.043522
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发表时间：
2013-04
影响因子：
5
通讯作者：
Yun Wang;Shuang Wang
中科院分区：
文献类型：
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作者：
Yun Wang;Shuang Wang
我们从普朗克首次发布的数据中得出距离先验，并根据当前的观测数据检查它们对暗能量约束的影响。我们给出了 {R, l_a, \Omega_b h^2, n_s} 的平均值和协方差矩阵，这给出了普朗克数据的有效总结。 CMB 偏移参数为 R=\sqrt{\Omega_m H_0^2}\,r(z_*) 和 l_a=\pi r(z_*)/r_s(z_*)，其中 z_* 是最后一个散射表面的红移，r(z_*) 和 r_s(z_*) 表示我们到 z_* 和声层的共动距离 分别为 z_*。我们发现普朗克距离先验比 WMAP9 的先验要紧得多。然而，与添加 WMAP9 距离先验相比，添加普朗克距离先验不会导致使用当前数据显着改善暗能量约束。这是因为普朗克数据似乎倾向于更高的物质密度和更低的哈勃常数，与大多数其他当前宇宙学数据集存在矛盾。在当前数据中添加普朗克距离先验会导致与平坦宇宙中的宇宙学常数出现边际不一致。
We derive distance priors from Planck first data release, and examine their impact on dark energy constraints from current observational data. We give the mean values and covariance matrix of {R, l_a, \Omega_b h^2, n_s}, which give an efficient summary of Planck data. The CMB shift parameters are R=\sqrt{\Omega_m H_0^2}\,r(z_*), and l_a=\pi r(z_*)/r_s(z_*), where z_* is the redshift at the last scattering surface, and r(z_*) and r_s(z_*) denote our comoving distance to z_* and sound horizon at z_* respectively. We find that Planck distance priors are significantly tighter than those from WMAP9. However, adding Planck distance priors does not lead to significantly improved dark energy constraints using current data, compared to adding WMAP9 distance priors. This is because Planck data appear to favor a higher matter density and lower Hubble constant, in tension with most of the other current cosmological data sets. Adding Planck distance priors to current data leads to a marginal inconsistency with a cosmological constant in a flat universe.