"But there may be another way. The early universe was chaotic and energetic, especially after inflation, the hypothesized event that triggered an incredible expansion event that ballooned our universe to tremendous sizes in less than a second. When inflation ended, space-time itself shook and vibrated with the released pent-up energies. The universe might have become so violent that random pockets of space-time could have spontaneously reached critical thresholds in density and size, thereby triggering the formation of "primordial" black holes that flooded the universe."
My notes. Important to read that the origin of PBHs in the early universe is the post-inflation epoch. When was this and how large was that postulated universe?
The ref paper, Ref - Primordial Black Holes Place the Universe in Stasis,
https://arxiv.org/abs/2212.01369, 29-March-2023.
From the 25-page PDF report cited, "I. INTRODUCTION In a broad class of inflationary scenarios, a population of black holes (BHs) is generated shortly after inflation as a consequence of the gravitational collapse of primordial density fluctuations. Such primordial black holes (PBHs) have received a significant amount of recent attention, in part because they can potentially provide a solution to the dark-matter problem. Indeed, while black holes evaporate over time as a consequence of Hawking radiation [1, 2], PBHs with masses M ~> 10^15 g would nevertheless have lifetimes longer than the age of the universe. Indeed, a population of PBHs with masses within the range 10^17 g <~ M <~ 10^23 g can potentially account for the entirety of the present-day dark-matter abundance, even when the spectrum of PBHs is approximately monochromatic (for reviews, see, e.g., Refs. [3-6]). PBHs with lower masses can also have implications for cosmology. Indeed, PBHs with masses in the range 10^9 g <~ M <~ 10^14 g evaporate at a significant rate during or after Big-Bang nucleosynthesis (BBN), generating energetic particles which can modify the primordial abundances of light nuclei. As a result, the abundance of PBHs with masses in this range is tightly constrained [4, 7, 8]."
My note. Inflation with PBHs apparently creates more constraints for the BB model, production of H, He, and perhaps a little Li too as well as DM creation. Is this another fine-tuning problem in cosmology using exotic physics, not seen operating in the universe today to explain how we evolved naturally?
Keep in mind, the missing primordial neutrinos needed too for BB model of origins. Looks like much tweaking is coming too
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