Primordial black holes and gravitational waves in multiaxion-Chern-Simons inflation
Primordial black holes and gravitational waves in multiaxion-Chern-Simons inflation
复制标题
DOI：
10.1103/physrevd.106.063532
复制
发表时间：
2022-06
影响因子：
5
通讯作者：
N. Mavromatos;V. Spanos;I. Stamou
中科院分区：
文献类型：
--
作者：
N. Mavromatos;V. Spanos;I. Stamou
在一个弦激发的两轴子场与Chern-Simons引力耦合的模型中，我们研究了膨胀的一些方面，以及增强原始黑洞(PBH)和引力波(GWS)产生的可能性，这导致了运行真空模型的膨胀。在这个模型中，尺度不变谱的涨落与宇宙学数据一致，是由弦紧致产生的轴子场的世界薄片(非微扰)瞬时项提供的。作为这种调制的结果，在这样的宇宙中，多溴联苯和GW的产生得到了增强，这可能导致在辐射时代GW的轮廓中的基本图案是可观察到的。此外，我们还证明了PBHs可能在这个宇宙中提供了大量的暗物质。为了进行比较，我们还讨论了传统弦激发的轴子单轴运动的两阶段膨胀宇宙学模型，同样涉及两个轴子场。由此产生的修正印在这两类模型之间的GWS光谱上是不同的，原则上可以通过未来的干涉仪来区分。我们考虑具有或多或少瞬时再加热的模型。我们还讨论了延长再加热时间对功率谱进一步增强的影响，从而进一步提高了多溴联苯中起暗物质作用的部分。
We study aspects of inflation and the possibility of enhanced production of primordial black holes (PBHs) and gravitational waves (GWs) in a string-inspired model of two axion fields coupled to Chern-Simons gravity, which results in a running-vacuum-model inflation. Fluctuations of the scale invariant spectrum, consistent with the cosmological data, are provided in this model by world-sheet (non-perturbative) instanton terms of the axion field arising from string compactification. As a result of such modulations, there is an enhanced production of PBHs and GWs in such cosmologies, which may lead to observable in principle patterns in the profile of GWs during the radiation era. Moreover, we demonstrate that the PBHs may provide a significant amount of Dark Matter in this Universe. For comparison, we also discuss a two-stage inflation cosmological model of conventional string-inspired axion monodromy, involving again two axion fields. The resulting modifications imprinted on the GWs spectra between these two classes of models are distinct, and can, in principle, be distinguished by future interferometers. We consider models with more or less instantaneous reheating. We also make some remarks on the effects of a prolonged reheating period in leading to further enhancement of the power spectrum and thus fractions of PBHs that play the role of Dark matter.