Intrinsic galaxy alignment from angular dependent primordial non-Gaussianity
Intrinsic galaxy alignment from angular dependent primordial non-Gaussianity
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DOI：
10.1088/1475-7516/2018/08/014
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发表时间：
2018-04
影响因子：
6.4
通讯作者：
Kazuhiro Kogai;T. Matsubara;A. Nishizawa;Y. Urakawa
中科院分区：
文献类型：
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作者：
Kazuhiro Kogai;T. Matsubara;A. Nishizawa;Y. Urakawa
在本文中，我们探索了具有整数自旋s大于或等于2的大质量场的可检测印记，这可以从弦理论中预测。结果表明，这样一个巨大的非零自旋场可以产生与两个波数夹角有关的压缩原始双谱。我们表明，考虑到来自大质量自旋-2场的贡献，角度相关的原始非高斯性（PNG）在星系对准的偏差参数中产生了很强的尺度依赖性，在小尺度上变得突出。作为角相关PNG的另一个例子，我们还考虑了原始双谱，其中角相关是由矢量场引入的，同时破坏了全局旋转对称。因此，我们发现b模宇宙剪切和非对角分量不会消失。这些方面与大量非零自旋场产生的PNG有质的区别。
In this paper, we explore a detectable imprint of massive fields with integer spins s ⩾ 2, which may be predicted from string theory. It was shown that such a massive non-zero spin field can generate the squeezed primordial bispectrum which depends on the angle between the two wavenumbers. We show that considering the contribution from the massive spin-2 field, the angular dependent primordial non-Gaussianity (PNG) yields a strong scale dependence in the bias parameter for the galaxy alignment, which becomes prominent at small scales. As another example of an angular dependent PNG, we also consider the primordial bispectrum where the angular dependence was introduced by a vector field, while breaking the global rotational symmetry. As a consequence, we find that the B-mode cosmic shear and non-diagonal components do not vanish. These aspects provide qualitative differences from the PNG sourced by massive non-zero spin fields.