Future detectability of gravitational-wave induced lensing from high-sensitivity CMB experiments
Future detectability of gravitational-wave induced lensing from high-sensitivity CMB experiments
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未来可通过高灵敏度宇宙微波背景实验探测引力波引起的透镜效应
DOI：
10.1103/physrevd.91.043531
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发表时间：
2015
影响因子：
5
通讯作者：
Atsushi Taruya
中科院分区：
文献类型：
--
作者：
Toshiya Namikawa;Daisuke Yamauchi;Atsushi Taruya
我们讨论了未来的高灵敏度宇宙微波背景（CMB）实验的引力波诱导透镜的可探测性。引力波可以引起弱透镜偏转角的旋转分量，通常被称为旋度模式，它会印在CMB图上。使用重构CMB图中涉及的透镜信号的技术，可以以无偏的方式测量这种卷曲模式，从而提供对B模式偏振实验的补充的引力波的独立确认。基于Fisher矩阵分析，我们首先表明，与噪音水平所需的确认的一致性关系的原始引力波，未来的CMB实验将能够检测引力波诱导的透镜信号。当张量与标量之比为时，即使一致性关系很难在高显著性水平上得到证实，引力波诱导的透镜效应也将在大于显著性水平上被检测到。此外，我们指出，高灵敏度的实验也将是强大的约束后产生的引力波的重组时代。与B模偏振相比，旋度模对低红移（）、低频率（）的引力波特别敏感，它可以对引力波的能量密度提供3个数量级以上的更严格的约束。
We discuss the future detectability of gravitational-wave induced lensing from high-sensitivity cosmic microwave background (CMB) experiments. Gravitational waves can induce a rotational component of the weak-lensing deflection angle, usually referred to as the curl mode, which would be imprinted on the CMB maps. Using the technique of reconstructing lensing signals involved in CMB maps, this curl mode can be measured in an unbiased manner, offering an independent confirmation of the gravitational waves complementary to B-mode polarization experiments. Based on the Fisher matrix analysis, we first show that with the noise levels necessary to confirm the consistency relation for the primordial gravitational waves, the future CMB experiments will be able to detect the gravitational-wave induced lensing signals. For a tensor-to-scalar ratio of, even if the consistency relation is difficult to confirm with a high significance, the gravitational-wave induced lensing will be detected at more thansignificance level. Further, we point out that high-sensitivity experiments will be also powerful to constrain the gravitational waves generated after the recombination epoch. Compared to the B-mode polarization, the curl mode is particularly sensitive to gravitational waves generated at low redshifts () with a low frequency (), and it could give a much tighter constraint on their energy densityby more than 3 orders of magnitude.