论文标题
全局21cm信号的原始黑洞和曲率扰动的限制
Constraints on primordial black holes and curvature perturbations from the global 21cm signal
论文作者
论文摘要
Ligo/Vigo对全球21cm信号的最新观察结果恢复了PBHS的兴趣。与以前的工作不同，我们研究了PBHS对质量范围$ 6 \ times 10^{13} {\ rm g} \ LINSESIM M _ {\ rm PBH} \ LINSESIM 3 \ times 10^{14} {14} \ rm g $的影响对IgM的影响。由于这些PBH的寿命小于宇宙的当今年龄，因此它们已经蒸发了。由于鹰辐射，PBHS对IgM的加热效应可以抑制全局21cm信号的吸收幅度。在这项工作中，通过要求在$ 10 \ sillesim z \ Lessim 30 $的红移范围内的全局21cm信号的差异亮度温度，例如，$Δt_{b} \ lyssim -100〜 \ rm mk $，我们在PBHS的初始质量分数上获得了上限。我们发现，最强的上限是$β_ {\ rm pbh} \ sim 2 \ times 10^{ - 30} $。由于PBHS的形成与原始曲率扰动有关，因此通过使用PBH的初始质量分数的约束，我们获得了量表范围$ 8.0 \ times times times times 10} {15} \ sime sim k \ sime k \ sims k \ sim k \ sims k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim k \ sim 1.8 \ 1.8 \ \ 16^^^16 mpc^{ - 1} $，对应于此处考虑的质量范围。我们发现最强的上限是$ \ Mathcal P _ {\ Mathcal R}（K）\ SIM 0.0046 $。通过与以前的作品进行比较，我们发现，对于在此工作中研究的质量范围（或比例范围），全局21厘米信号或21cm功率谱应该对PBHS的初始质量分数和原始曲率扰动的功率谱的初始质量分数给出最大的上限。
The recent observations of the global 21cm signal by EDGES and gravitational waves by LIGO/VIGO have revived interest in PBHs. Different from previous works, we investigate the influence of PBHs on the evolution of the IGM for the mass range $6\times 10^{13} {\rm g} \lesssim M_{\rm PBH}\lesssim 3\times 10^{14} \rm g$. Since the lifetime of these PBHs is smaller than the present age of the Universe, they have evaporated by the present day. Due to Hawking radiation, the heating effects of PBHs on the IGM can suppress the absorption amplitude of the global 21cm signal. In this work, by requiring that the differential brightness temperature of the global 21cm signals in the redshift range of $10\lesssim z \lesssim 30$, e.g., $δT_{b} \lesssim -100~\rm mK$, we obtain upper limits on the initial mass fraction of PBHs. We find that the strongest upper limit is $β_{\rm PBH} \sim 2\times 10^{-30}$. Since the formation of PBHs is related to primordial curvature perturbations, by using the constraints on the initial mass fraction of PBHs we obtain the upper limits on the power spectrum of primordial curvature perturbations for the scale range $8.0\times 10^{15}\lesssim k \lesssim 1.8\times 10^{16}~\rm Mpc^{-1}$, corresponding to the mass range considered here. We find that the strongest upper limit is $\mathcal P_{\mathcal R}(k) \sim 0.0046$. By comparing with previous works, we find that for the mass range (or the scale range) investigated in this work the global 21cm signals or the 21cm power spectrum should give the strongest upper limits on the initial mass fraction of PBHs and on the power spectrum of primordial curvature perturbations.
