Broken blue-tilted inflationary gravitational waves: a joint analysis of NANOGrav 15-year and BICEP/Keck 2018 data
Broken blue-tilted inflationary gravitational waves: a joint analysis of NANOGrav 15-year and BICEP/Keck 2018 data
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DOI：
10.1088/1475-7516/2024/05/004
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发表时间：
2023-07
影响因子：
6.4
通讯作者：
Jun-Qian Jiang;Yong Cai;Gen Ye;Yun-song Piao
中科院分区：
文献类型：
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作者：
Jun-Qian Jiang;Yong Cai;Gen Ye;Yun-song Piao
最近，脉冲星计时阵列（PTA）合作报告了纳赫兹波段随机引力波背景（SGWB）的证据。暴胀引力波（IGW）的频谱是未知的，它在不同的频段可能呈现不同的幂律，因此如果PTA信号是原始的，那么利用当前的PTA和CMB数据研究IGW的潜在意义将是非常有意义的。在这封信中，我们使用NANOGrav 15年和BICEP/Keck 2018数据对IGW的破幂律谱进行了联合马尔可夫链蒙特卡罗分析。发现在PTA波段，IGW的最佳拟合谱倾斜为nPTA T = 2.42+0.32 - 0.91，而在CMB波段，最佳拟合谱倾斜为nCMB T = 0.55+0.37 - 0.10，而r的可探测幅度与nCMB T = 0.50仍是相容的。我们的结果的通货膨胀的影响进行了讨论。
Recently, the pulsar timing array (PTA) collaborations have reported the evidence for a stochastic gravitational wave background (SGWB) at nano-Hertz band. The spectrum of inflationary gravitational wave (IGW) is unknown, which might exhibit different power law at different frequency-bands, thus if the PTA signal is primordial, it will be significant to explore the underlying implications of current PTA and CMB data on IGW. In this Letter, we perform a joint Markov Chain Monte Carlo analysis for a broken power-law spectrum of IGW with the NANOGrav 15-year and BICEP/Keck 2018 data. It is found that though the bestfit spectral tilt of IGW at PTA band is n PTA T = 2.42+0.32 -0.91, at CMB band the bestfit is n CMB T = 0.55+0.37 -0.10 while a detectable amplitude of r with n CMB T ≃ 0 is still compatible. The implication of our results for inflation is also discussed.