General quadrupolar statistical anisotropy: Planck limits
General quadrupolar statistical anisotropy: Planck limits
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一般四极统计各向异性：普朗克极限
DOI：
10.1088/1475-7516/2017/03/039
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发表时间：
2016
影响因子：
6.4
通讯作者：
F. Urban
中科院分区：
文献类型：
--
作者：
S. Ramazanov;G. Rubtsov;Mikjel Thorsrud;F. Urban
几个早期的宇宙场景预测了原始曲率扰动的方向依赖谱。这转化为宇宙微波背景辐射的统计各向同性的违反。以往对统计各向异性的研究主要集中在以单个多极矢量和总体幅度g*为特征的四极方向依赖性上。然而，一般来说，四极杆具有更复杂的几何形状，由两个多极矢量和g*描述。这就是本文的主题。特别是，我们利用Planck 2015地图限制了不同形状的四极子的振幅g*。我们还约束了某些预测这种更一般的四极统计各向异性的暴胀情景。
Several early Universe scenarios predict a direction-dependent spectrum of primordial curvature perturbations. This translates into the violation of the statistical isotropy of cosmic microwave background radiation. Previous searches for statistical anisotropy mainly focussed on a quadrupolar direction-dependence characterised by a single multipole vector and an overall amplitude g*. Generically, however, the quadrupole has a more complicated geometry described by two multipole vectors and g*. This is the subject of the present work. In particular, we limit the amplitude g* for different shapes of the quadrupole by making use of Planck 2015 maps. We also constrain certain inflationary scenarios which predict this kind of more general quadrupolar statistical anisotropy.