We study how the bounds on the abundance of Primordial Black Holes (PBHs) and the constraints on power spectrum are modified if a non-standard evolution phase takes place between the end of inflation and the Standard radiation-dominated (RD) universe after inflation. The constraints on PBH abundance and power spectrum are computed using the new, freely available, https://github.com/TadeoDGAguilar/PBHBeta PBHBeta library, which accounts for the effects of non-standard expansion and specific criteria for PBH formation in such non-standard scenarios. As working examples, we consider three different cases: a pure matter-dominated (MD) phase, a scalar field-dominated (φD) universe, and a stiff fluid-dominated (SD) scenario. While the background expansion is the same for the MD and φD scenarios, the PBH formation criteria lead to different constraints to power spectrum. On the other hand, the duration of the non-standard expansion phase alters the bounds, with longer MD periods resulting in weaker constraints on power spectrum, and longer SD scenarios leading to an enhanced abundance due to the dust-like redshifting of PBHs. The modifications to the constraints are reported in all cases and we highlight those where the power spectrum may be significantly constrained.

中文翻译：

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非标准宇宙学对原始黑洞的约束


我们研究了如果在膨胀结束和膨胀后的标准辐射主导 （RD） 宇宙之间发生非标准演化阶段，如何修改原始黑洞 （PBH） 的丰度边界和功率谱的约束。对 PBH 丰度和功率谱的约束是使用新的、免费提供的 https://github.com/TadeoDGAguilar/PBHBetaPBHBeta 库计算的，该库考虑了非标准扩展的影响和此类非标准情况下 PBH 形成的特定标准。作为工作示例，我们考虑了三种不同的情况：纯物质主导 （MD） 相、标量场主导 （φD） 宇宙和刚性流体主导 （SD） 情景。虽然 MD 和 φD 场景的背景扩展相同，但 PBH 形成标准导致对功率谱的不同约束。另一方面，非标准膨胀阶段的持续时间改变了边界，较长的 MD 周期导致对功率谱的约束较弱，而较长的 SD 情景由于 PBH 的尘埃状红移导致丰度增加。在所有情况下都会报告对约束的修改，并重点介绍那些功率谱可能受到显著约束的情况。