Did BICEP2 see vector modes? First B-mode constraints on cosmic defects.
Did BICEP2 see vector modes? First B-mode constraints on cosmic defects.
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DOI：
10.1103/physrevlett.112.171302
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发表时间：
2014-03
影响因子：
8.6
通讯作者：
A. Moss;L. Pogosian
中科院分区：
文献类型：
--
作者：
A. Moss;L. Pogosian
宇宙缺陷的缩放网络，例如弦和纹理，在整个宇宙的历史中主动生成标量、矢量和张量度量扰动。特别是，由缺陷产生的矢量模式是宇宙微波背景 B 模式偏振的有效来源。我们使用最近发布的 BICEP2 和 POLARBEAR B 模式偏振光谱来约束各种不同类型的宇宙弦网络的属性。我们发现，为了让字符串本身提供令人满意的拟合，有效字符串间距离需要非常大——最适合数据的光谱更能代表全局字符串和纹理。当局部弦贡献与膨胀 B 模式谱一起考虑时，拟合度会得到改善。我们讨论这些结果对预测宇宙缺陷的理论的影响。
Scaling networks of cosmic defects, such as strings and textures, actively generate scalar, vector, and tensor metric perturbations throughout the history of the Universe. In particular, vector modes sourced by defects are an efficient source of the cosmic microwave background B-mode polarization. We use the recently released BICEP2 and POLARBEAR B-mode polarization spectra to constrain properties of a wide range of different types of cosmic strings networks. We find that in order for strings to provide a satisfactory fit on their own, the effective interstring distance needs to be extremely large--spectra that fit the data best are more representative of global strings and textures. When a local string contribution is considered together with the inflationary B-mode spectrum, the fit is improved. We discuss implications of these results for theories that predict cosmic defects.