Are there any black holes left over from the Big Bang?

rod

Oct 22, 2019
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This article is refreshing to read. There are not many *popular* science site reports on primordial black holes (PBH) in BB cosmology model it seems. The space.com article said "The early universe was, to say the least, a crazy place. Temperatures and pressures unheard of in the eons since. Phase changes that rocked the entire cosmos. Transformations that rewrote the very laws of nature. Back then, if conditions were right, any old patch of gas may have spontaneously shrunk itself to form a black hole of any size: from something weighing just a few kilograms to thousands of times the mass of the sun, and anything in between. For every theoretical physicist working on the problem of these so-called primordial black holes, there is at least one hypothetical mechanism for generating them, involving everything from inflation theory to colliding universes."

There are newer reports out that Planet Nine could be a 5 earth mass PBH. Here is another new report on PBH.

“Primordial black holes (PBHs) can form in the early Universe through a variety of mechanisms and can account for all or part of the dark matter (DM) (e.g. [1–25]). PBHs surviving until present can span many orders of magnitude in mass, from 10^15 g to well over 10^10 Msun, and they can account for the entirety of the DM in the mass window ~ 10^−16 – 10^−10Msun, where there are no observational constraints [26–28]. PBHs with sublunar masses can play a role in the synthesis of heavy elements, production of positrons, as well as other astrophysical phenomena [29–31]. PBHs with larger masses can account for some of the gravitational wave events detected by LIGO [32–34] as well as seed supermassive black holes [35–37]. The mass window of 10 – 10^3Msun is particularly interesting in connection with signals observed by LIGO [37–43]." ref - Constraining Primordial Black Holes with Dwarf Galaxy Heating, https://ui.adsabs.harvard.edu/abs/2020arXiv200702213L/abstract, July 2020.

It seems at the present, PBH model(s) can be all over the map :)
 
Mar 19, 2020
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Ever since learning about their possibility, Primordial Black Holes (PBHs) have been a pet interest. Of course every time I post about them, there are the inevitable "he-haw, what a dopey idea" responses. But with the detection of GWs and such large black holes merging, more interest has been focused on the potential formation and existence of PBHs. There now seems to be a little less he-hawing then previously encountered. Perhaps some of it has retreated to the cosmic closet.

On studying the hypothetical nature of Pop. III stars that supposedly formed all the super massive BHs of the early universe, and the seeds of galaxy formation, I ran across an interesting article about PBHs. It described an alternate formation mechanism for BHs, very distinct from the "must-come-from-a-star" dogma. The process, as some of you are aware (and probably he-haw about), results in what are called "Direct Collapse Black Holes" (DCBHs). These form simply by sufficient masses of primordial hydrogen (mostly) to collapse to a BH without a stellar precursor. Of course none of these concepts rule out the formation of massive stars at the same time, which did/might undergo "standard" core-collapse.

Having zero expertise in this subject, it seemed like a prime area of study. Reports from the deepest observations reveal that the age of the earliest quasars indicate that large black holes formed much earlier than could have been made by the continuous accretion of smaller BH mergers. Due to their size and early age estimates, such objects could very well provide evidence to support PBHs that formed by a direct collapse mechanism.

A brief search for such objects turned up two that appear to be the most distant observed to date. And time-wise, they should not exist according to standard model(s) of the early universe. For instance, Quasar ULAS J1342+0928* has a mass estimated at 800 million SMs, and ca. 690 million years old. And it is not alone. Another quasar, ULAS J1120+0641** has an estimated mass of ca. 2 x 10E9 SMs***, and is ca. 770 million years old. Again, they are not supposed to be there at this early stage, or so I have read (and no retractions have been encountered).

This data on the earliest quasars could support the formation of PBHs by DCBH formation. Of course data on such objects is rather limited, probably since they are not supposed to be there, and it seems that a lot of people would rather ignore them than modify their absolute certainties about the nature of the BB and everything that came out of it. Perhaps their dogma insists on it.

One of the interesting concepts of PBHs is that they can form in almost any size, and might answer some questions about the nature of the observable universe. And they are a known object that exists in the universe (no exotic matter required). So it is with considerable interest that I find a story on these PBHs here on space.com that actually supports the concept. Do you suppose supporters of such notions will be burned at the stake?

It seems likely there are many more of these "early" quasars, they just haven't been found since the current instruments to detect them are limited, and many could be much younger, based simply on the size of the two noted above. It may simply boil down to a need for more sophisticated instruments. If they keep finding younger and younger quasars, it would seem there is a problem somewhere in some BB theories.

This is one biochemist's view on the issue, admittedly a tad outside his expertise. And do remember, that in all of science, one's concepts are only as good as the data. Any suggestions, one way or another, would be entertaining!


* https://en.wikipedia.org/wiki/ULAS_J1342+0928


** https://en.wikipedia.org/wiki/ULAS_J1120+0641


*** A luminous quasar at a redshift of z = 7.085 (Nature)



Did I just hear a he-haw?!
 
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Reactions: Catastrophe
Feb 3, 2020
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So, Black Holes, primordial or otherwise, may account for a large percentage of dark mass? But, Dark Mass drives expansion? Seems counter intuitive.
 
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Mar 19, 2020
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Not being a serious advocate of PBHs as dark matter candidates (yet), only that they cannot be ruled out. There are other things that may be better contenders. But you have an eye for reading between the lines, KC.

PBHs as seeds for SMBHs at the earliest possible time for DCBH formation is another matter. That seems a more likely probability since they are seen so early in those very distant quasars, and are very large. There are earlier images of galaxies* (higher redshift) than these quasars, but the quasars are confirmed black holes, with well established mass and age. That is the biggest issue.

As I recall, dark energy may be involved in expansion. Suppose that is one too look up some time. Really like to deal with things you can see, either optically or with instruments. That is the great thing about earth-bound sciences. You get real data that does not require modelling, only proper interpretation. This is true in a green-house, or over at the Large Hadron Collider!

Perhaps some experts on dark energy, assuming such an accolade exists, might help us out on this one.

* https://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects
 
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Feb 18, 2020
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I see no problem with PBHs. Everything is a matter of proportion. Some will. Some won't. Just like direct ionisation in diffused ionized gas - not in clouds, singly in gas. Last I heard it is not understood, except obviously it is by O and B stars. Any more recent suggestions would be welcome :)
 
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Jul 18, 2020
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Sigh. Black holes are the only type of "dark matter". Black holes' gravity is the only "dark energy". Our miniverse is an infinitesimal part of the UNIVERSE. The number of black holes in the UNIVERSE > the number of stars in our miniverse. Our miniverse formed galaxies IMMEDIATELY after the "big bang" because it was orbited by millions of black holes. (See, e.g., the swarm of black holes orbiting Sagittarius *A.)

Once we recognize these scientific facts, modern cosmology will take its rightful place on a dusty shelf along with Plato's and Copernicus's. And human beings will, again, be humbled by their insignificance.

OTOH, humility is the only road to truth.
 

rod

Oct 22, 2019
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FYI. PBH are used in a newer model to explain Planet Nine now, perhaps a 5 earth mass PBH. This type of model can be applied to exoplanet studies too. If the early universe in the BB cosmology created an abundance of PBH, what happens to star formation theories and exoplanets? Will PBH contribute to unstable exoplanet systems? It seems all manner of PBH modeling can now be developed to show if exoplanets can be stable and suitable for life or just plain, destructive. The door is now wide open for exoplanets studies and PBH impact :)
 

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