Like father, like son, or is it grandson?
Once again, did primordial black holes (PBHs) appear from the get?
As noted by more than a few cosmologists*, the formation and existence of PBHs is an active study of research and this new data adds more support for their existence. Yeah, I know, there will be a lot of "oh brother"s out there on this one, but this data indicates PBHs are more "in the running" then ever before.
The link below gives a good overview on how they are considered, but cannot include all PBH sources since this stuff is too wild to know what other sources might have existed way back when. Note that there is no limit to the size of a PBH.
As someone once noted, "All models (aka simulations) are wrong, but some are useful." And as rod has so famously pointed out, the Department of Cosmology doesn't like alternatives to their perceived "Laws of the BB."
Did they arise intact from the BB, or form shortly afterwards from ultra-dense clouds? Sadly, it is likely no one will ever know. But perhaps, if and when that blasted Webb Telescope** makes its appearance in the seemingly ever distant future, it might provide an answer, or two. Or at least more suggestions for the modelers.
Happily then, for those who believe they exist, they can never be disproven! So to any nay-sayers out there, the preemptive answer to their intransigence? Prove that they do not exist. Because all those models of SMBHs forming shortly after the BB might have just fallen into a SMPBH, never to return.