论文标题
低尺度核发生的重力波
Gravitational Waves-Tomography of Low-Scale-Leptogenesis
论文作者
论文摘要
一个长寿命的标量字段（$φ$），它与右手（rh）中微子（$ n_ {ri} $）薄弱地结合起来，在低规模的胶质发生（LSL）机制中生成了小的RH Neutmino质量（$ M_I $），尽管具有很大的真空真空效率预期值$v_φ$v_φ$。在这种情况下，$ m_i $ s与$φ$驱动的非标准宇宙历史的持续时间共享的相关性为研究原始重力波（GWS）的LSL签名提供了绝佳的机会。我们发现它具有吸引力，特别是针对由于通货膨胀的蓝倾张量功率谱而起源的引力波，并通过非标准的宇宙时期传播。从广义上讲，根据$ m_i $的不同，该方案有两个重大的后果。首先，如果LSL在发挥作用，则具有较大蓝色倾斜的GWS也不会矛盾，即使对于具有非常高尺度重新加热的通货膨胀模型，大爆炸核合成（BBN）即使是束缚的。其次，它可以通过低频和互补的高频测量来探测LSL的可能性，而GW频谱形状通常是双峰。对于一项案例研究，我们将Pulsar-Timing阵列（PTA）的GWS的最新结果视为低频下的“测量”，并预测了较高频率下LSL机制的特征。
A long-lived scalar field ($Φ$) which couples weakly to the right-handed (RH) neutrinos ($N_{Ri}$), generates small RH neutrino masses ($M_i$) in Low-Scale-Leptogenesis (LSL) mechanisms, despite having a large vacuum expectation value $v_Φ$. In this case, the correlation shared by the $M_i$s and the duration of the non-standard cosmic history driven by the $Φ$ provides an excellent opportunity to study LSL signatures on primordial gravitational waves (GWs). We find it engaging, specifically for the gravitational waves that originate due to the inflationary blue-tilted tensor power spectrum and propagate through the non-standard cosmic epoch. Depending on $M_i$, broadly, the scenario has two significant consequences. First, if LSL is at play, GWs with a sizeable blue tilt do not contradict the Big-Bang-Nucleosynthesis (BBN) bound even for the post-inflationary models with very high-scale reheating. Second, it opens up a possibility to probe LSLs via a low-frequency and a complementary high-frequency measurement of GW-spectral shapes which are typically double-peaked. For a case study, we consider the recent results on GWs from the Pulsar-Timing-Arrays (PTAs) as a `measurement' at the low frequencies and forecast the signatures of LSL mechanisms at the higher frequencies.
