Probing polarization states of primordial gravitational waves with CMB anisotropies
Probing polarization states of primordial gravitational waves with CMB anisotropies
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发表时间：
2019
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通讯作者：
S. Saito;K. Ichiki;A. Taruya
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作者：
S. Saito;K. Ichiki;A. Taruya
讨论了压印在宇宙微波背景各向异性中的原始引力波的偏振特征。超弦理论或M理论所激发的高能物理一般会产生宇称破坏项，这可能会在膨胀过程中产生圆极化引力波背景(GWB)。与非极化GWB的标准暴胀预测相反，圆极化GWB产生了CMB各向异性的非零Tb和EB模功率谱。我们计算了TB和EB模功率谱，考虑了再电离引起的次级各向异性，并研究了宇宙学参数的依赖关系。然后，我们从大角度尺度(L，≤，16)的三年WMAP数据讨论了当前对圆偏振地球宽带的限制。基于参数估计的蒙特卡罗分析，还讨论了未来的CMB实验的前景，表明圆极化度ε，即用总振幅归一化的左右手模式张量功率谱的不对称性，可以测量到|ε|∼0.35(r/0.05)。探测原始引力波的偏振态2
We discuss the polarization signature of primordial gravitational waves imprinted in cosmic microwave background (CMB) anisotropies. The high-energy physics motivated by superstring theory or M-theory generically yields parity violating terms, which may produce a circularly polarized gravitational wave background (GWB) during inflation. In contrast to the standard prediction of inflation with un-polarized GWB, circularly polarized GWB generates non-vanishing TB and EB-mode power spectra of CMB anisotropies. We evaluate the TB and EB-mode power spectra taking into account the secondary anisotropies induced by the reionization and investigate the dependence of cosmological parameters. We then discuss current constraints on the circularly polarized GWB from large angular scales (l ≤ 16) of the three year WMAP data. Prospects for future CMB experiments are also investigated based on a Monte Carlo analysis of parameter estimation, showing that the circular polarization degree, ε, which is the asymmetry of the tensor power spectra between rightand left-handed modes normalized by the total amplitude, can be measured down to |ε|∼ 0.35(r/0.05). Probing polarization states of primordial gravitational waves 2