标题： 用原初黑洞限制$F(R)$震荡宇宙学模型 显示英文标题

标题： Constraining $F(R)$ bouncing cosmologies with primordial black holes

摘要： 原始黑洞（PBH）物理学的理论现象及其相关的PBH丰度限制可以用来探测早期宇宙的物理。在这项工作中，我们通过研究早期F(R)修正引力阶段的影响来探讨标准辐射主导时期PBH的形成，这一阶段具有反弹行为，旨在避免初始时空奇点问题。具体来说，我们计算了视界穿越时刻的能量密度功率谱，然后利用峰理论提取了我们手头的$\alpha$参数的$F(R)$引力反弹模型中的PBH丰度。有趣的是，我们发现为了避免大爆炸核合成（BBN）之前的早期PBH主导时代产生过多的引力波，$\alpha$应位于$\alpha\leq 10^{-19}M^2_\mathrm{Pl}$范围内。这一限制可以转化为对热大爆炸（HBB）阶段开始时能量尺度的约束，$H_\mathrm{RD}\sim \sqrt{\alpha}/2$，它可以重新表述为$H_\mathrm{RD}< 10^{-10}M_\mathrm{Pl}$。 显示英文摘要

摘要： The phenomenology of primordial black hole (PBH) physics and the associated PBH abundance constraints, can be used in order to probe the physics of the early Universe. In this work, we investigate the PBH formation during the standard radiation-dominated era by studying the effect of an early F(R) modified gravity phase with a bouncing behavior which is introduced to avoid the initial spacetime singularity problem. In particular, we calculate the energy density power spectrum at horizon crossing time and then we extract the PBH abundance in the context of peak theory as a function of the parameter $\alpha$ of our $F(R)$ gravity bouncing model at hand. Interestingly, we find that in order to avoid GW overproduction from an early PBH dominated era before Big Bang Nucleosynthesis (BBN), $\alpha$ should lie within the range $\alpha\leq 10^{-19}M^2_\mathrm{Pl}$. This constraint can be translated to a constraint on the energy scale at the onset of the Hot Big Bang (HBB) phase, $H_\mathrm{RD}\sim \sqrt{\alpha}/2$ which can be recast as $H_\mathrm{RD}< 10^{-10}M_\mathrm{Pl}$.