Gravitational waves and dark radiation from dark phase transition: Connecting NANOGrav pulsar timing data and hubble tension
Gravitational waves and dark radiation from dark phase transition: Connecting NANOGrav pulsar timing data and hubble tension
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DOI：
10.1016/j.physletb.2021.136238
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发表时间：
2020-09
期刊：
影响因子：
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通讯作者：
Y. Nakai;Motoo Suzuki;F. Takahashi;Masaki Yamada
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文献类型：
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作者：
Y. Nakai;Motoo Suzuki;F. Takahashi;Masaki Yamada
最近NANOGrav合作报告的脉冲星计时数据可能表明在f 10− 8 Hz附近存在随机引力波背景。我们探索了从暗扇区相变中产生这种低频引力波的可能性。假设暗区除了引力相互作用外与可见区完全解耦，我们发现一定量的暗辐射应该保留到现在。NANOGrav的数据表明，暗辐射的数量接近目前的上限，这可能有助于缓解所谓的哈勃张力。如果暗辐射的存在在未来的CMB-S4实验中没有得到证实，这将意味着存在新的粒子，它们在O（1-100）MeV的能量尺度上与标准模型扇区发生微弱的相互作用。
Recent pulsar timing data reported by the NANOGrav collaboration may indicate the existence of a stochastic gravitational wave background around f∼ 10− 8 Hz. We explore a possibility to generate such low-frequency gravitational waves from a dark sector phase transition. Assuming that the dark sector is completely decoupled from the visible sector except via the gravitational interaction, we find that some amount of dark radiation should remain until present. The NANOGrav data implies that the amount of dark radiation is close to the current upper bound, which may help mitigate the so-called Hubble tension. If the existence of dark radiation is not confirmed in the future CMB-S4 experiment, it would imply the existence of new particles feebly interacting with the standard model sector at an energy scale of O (1-100) MeV.