Concordance cosmology?
Concordance cosmology?
复制标题
一致性宇宙学？
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
E. Rozo
中科院分区：
文献类型：
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作者：
Youngsoo Park;E. Rozo
我们提出了一个新的直观的度量两个实验之间的张力，并将其应用到几个数据集。虽然我们的指标是非最佳的，但如果检测到紧张的证据，这个证据是强大的，易于解释。假设一个平坦的$\Lambda$CDM宇宙学模型，我们发现，有一个适度的2.2\sigma $之间的DES第1年的结果和宇宙微波背景（CMB）的${\it普朗克}$测量紧张。这种张力是由在晚期宇宙中观察到的结构数量与拟合普朗克数据预测的结构数量之间的差异驱动的，似乎与普朗克和哈勃速率的局部估计之间的张力无关。特别是，结合DES，重子声振荡（BAO），大爆炸核合成（BBN）和超新星（SNe）测量恢复哈勃常数和声音地平线符合${\it普朗克}$，并在紧张与当地距离阶梯测量。如果这些不同的数据集之间的紧张关系持续存在，那么调和当前的数据可能需要至少以两种不同的方式打破平坦的CDM模型：一种涉及早期宇宙中的新物理，另一种涉及新的晚期宇宙物理。
We propose a new intuitive metric for evaluating the tension between two experiments, and apply it to several data sets. While our metric is non-optimal, if evidence of tension is detected, this evidence is robust and easy to interpret. Assuming a flat $\Lambda$CDM cosmological model, we find that there is a modest $2.2\sigma$ tension between the DES Year 1 results and the ${\it Planck}$ measurements of the Cosmic Microwave Background (CMB). This tension is driven by the difference between the amount of structure observed in the late-time Universe and that predicted from fitting the ${\it Planck}$ data, and appears to be unrelated to the tension between ${\it Planck}$ and local esitmates of the Hubble rate. In particular, combining DES, Baryon Acoustic Oscillations (BAO), Big-Bang Nucleosynthesis (BBN), and supernovae (SNe) measurements recovers a Hubble constant and sound horizon consistent with ${\it Planck}$, and in tension with local distance-ladder measurements. If the tension between these various data sets persists, it is likely that reconciling ${\it all}$ current data will require breaking the flat $\Lambda$CDM model in at least two different ways: one involving new physics in the early Universe, and one involving new late-time Universe physics.