Antipodal angular correlations of inflationary stochastic gravitational wave background
Antipodal angular correlations of inflationary stochastic gravitational wave background
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暴胀随机引力波背景的对映角相关性
DOI：
10.1103/physrevd.107.023503
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发表时间：
2023
影响因子：
5
通讯作者：
Saito Ryo
中科院分区：
文献类型：
--
作者：
Wu Zhen-Yuan;Sakai Nobuyuki;Saito Ryo
暴胀随机引力波背景（SGWB）的测量是未来GW实验的主要目标之一。在直接GW实验中，实现它的障碍是将通货膨胀的SGWB与其他类型的SGWB隔离开来。在本文中，作为一个可区分的签名，通货膨胀的SGWB，我们认为可检测的普遍性质：对映相关，即，来自相反方向的GW的相关性，作为视界再入的结果。已知相位相干方法对于检测SGWB中的角度相关性是无用的，这是由于擦除信号的有问题的相位因子。因此，我们调查我们是否可以构建一个相位不相干估计的强度图中的对映相关性。我们发现，这一结论取决于暴胀引力波是否具有统计各向同性。在具有统计均匀性和各向同性的标准暴胀模型中，没有一个估计量对对极相关性敏感，但不受有问题的相位因子的影响。另一方面，对于具有统计各向异性的暴胀模型，也有可能找到对映相关的非零估计。来自各向同性膨胀的SGWB与其他组分是不同的。
The measurement of the inflationary stochastic gravitational wave background (SGWB) is one of the main goals of future GW experiments. In direct GW experiments, an obstacle to achieving it is the isolation of the inflationary SGWB from the other types of SGWB. In this paper, as a distinguishable signature of the inflationary SGWB, we argue the detectability of its universal property: antipodal correlations, i.e., correlations of GWs from the opposite directions, as a consequence of the horizon reentry. A phase-coherent method has been known to be of no use for detecting the angular correlations in SGWB due to a problematic phase factor that erases the signal. We thus investigate whether we can construct a phase-incoherent estimator of the antipodal correlations in the intensity map. We found that the conclusion depends on whether the inflationary GWs have statistical isotropy or not. In the standard inflationary models with statistical homogeneity and isotropy, there is no estimator that is sensitive to the antipodal correlations but does not suffer from the problematic phase factor. On the other hand, it is possible to find a nonvanishing estimator of the antipodal correlations for inflationary models with statistical anisotropy. SGWB fromanisotropicinflation is distinguishable from the other components.