Tension between the power spectrum of density perturbations measured on large and small scales
Tension between the power spectrum of density perturbations measured on large and small scales
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DOI：
10.1103/physrevd.91.103508
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发表时间：
2014-09
影响因子：
5
通讯作者：
R. Battye;T. Charnock;A. Moss
中科院分区：
文献类型：
--
作者：
R. Battye;T. Charnock;A. Moss
在利用宇宙微波背景（CMB）推断的密度扰动功率谱的幅度测量和在较小尺度上直接通过大尺度结构（LSS）测量之间存在着紧张关系。我们表明，这种紧张局势存在，是强大的，一系列的LSS指标，包括集群，透镜和红移空间扭曲，并使用CMB数据从普朗克或WMAP + SPT/ACT。一个明显的方法来试图调和这一点是包括一个大质量的中微子，它可以是活跃的或无菌的。使用普朗克和所有LSS数据的组合，我们发现（i）对于活性中微子，Sigma m（nu）=（0.357 +/- 0.099）eV;（ii）对于无菌中微子，m（无菌）（eff）=（0.67 +/- 0.18）eV，Delta N-eff = 0.32 +/- 0.20。然而，这是以普朗克温度数据的退化拟合为代价的，我们分别对大质量中微子和无菌中微子在2.5 σ和1.6 σ处的剩余张力进行了量化。我们还考虑了其他的解释，包括较低的再电离红移，这将与WMAP和特设修改原始功率谱的偏振测量相冲突。
There is a tension between measurements of the amplitude of the power spectrum of density perturbations inferred using the cosmic microwave background (CMB) and directly measured by large-scale structure (LSS) on smaller scales. We show that this tension exists, and is robust, for a range of LSS indicators including clusters, lensing and redshift space distortions and using CMB data from either Planck or WMAP + SPT/ACT. One obvious way to try to reconcile this is the inclusion of a massive neutrino which could be either active or sterile. Using Planck and a combination of all the LSS data we find that (i) for an active neutrino Sigma m(nu) = (0.357 +/- 0.099) eV and (ii) for a sterile neutrino m(sterile)(eff) = (0.67 +/- 0.18) eV and Delta N-eff = 0.32 +/- 0.20. This is, however, at the expense of a degraded fit to Planck temperature data, and we quantify the residual tension at 2.5 sigma and 1.6 sigma for massive and sterile neutrinos, respectively. We also consider alternative explanations including a lower redshift for reionization that would be in conflict with polarization measurements made by WMAP and ad hoc modifications to the primordial power spectrum.