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In hopes of not "rocking" the boat, I am extremely curious to know where the information that was contained in the "original" singularity came from?...

From my very minuscule understanding of astronomy to my chagrin, I haven't been able to find a reasonable "scientific" explanation for this question!...

In advance, please forgive my undesired ignorance...I am trying to learn!!!.....
As Cat states, the singularity requires extrapolation.

The equations of physics go nuts when closer than ~ 1E-40 sec. Direct evidence for the physics is found only after about 1E-12 sec. thanks to the LHC. It’s metaphysics that is used to address earlier events.

One of the first solutions to GR (General Relativity), oddly, was of black holes (Schwarzshild) but it was deemed highly speculative — good math, but maybe bad physics. But a BH solution doesn’t require an actual singularity.
 
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Helio,As I remember it, and it was a very long time ago, ;) I am sure that it was not 100% perfectly regularly spaced out particles with no local concentrations whatsoever.

But I do acknowledge that some form of vibration could well trigger accretion.
I suspect the inverse square law gives gravity the edge needed to trigger collapse even though the pressure wave from a SN bumps the KE.

The virial theorem addresses this.
 

Catastrophe

"There never was a good war, or a bad peace."
Helio, re: accretion
So something has to trigger them in order to create fragmentation, whereby many of these fragments will reach a density state that will allow a full collapse to form a star. Supernovae explosions will blast into a cloud compressing it, which can trigger collapse. See Jeans Instability.
But clouds are not purely homogenous. Events, internal and external, will produce flows within the cloud. Given their low density, these flows can become supersonic, which produces shockwaves that can, in theory, trigger fragmentation and collapse.
Let us not forget dark matter:
Long before there were any galaxies, the dark matter began to gather together into enormous clouds. It was the gravity of these clouds that attracted and pulled together the atoms that would ultimately go on to form galaxies themselves. From observations such as these, we have not only been able to measure how much dark matter there is in our universe, but have also learned a limited amount about its nature.
Hooper (Kindle) page 107.

Presumably this dark matter will still be around, when it comes to star formation? In particular, DM must help provide something to contain SN vibrations?

Cat :)

Vide:

Dark matter is thought to make up most of the mass of the universe. However since it doesn't interact with light in the same way as normal matter, it can only be observed through its gravitational effects. The key to studying it may however lie in how stars are formed in these galaxies.3 Jan 2019 Original bold.

Dark matter on the move | University of Surrey
 
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All this hypothesizing about how dark matter behaves seems awfully speculative, since we believe that it doesn't interact with normal matter except by gravitational attraction.

So, is it the same temperature as the normal matter? If assumed so, why? How would energy transfer between it and normal matter?

Does it have "black matter pressure" by interacting with itself, or can it collapse by gravity without any regard to temperature of itself, not to mention the matter around it? Whatever you think, why do you think that?

It seems some theorists are eager to postulate things that make their theories seem plausible, while not pursuing the related concepts that could derail their theories.

We are to the point of inferring about 95% of the matter/energy in the universe is things that we do not understand and that do not follow the rules of the 5% that we do understand. Yet, we keep applying those rules to the other 95% whenever we don't have proof that they don't apply. Not logical.

Once we get past the CBR to earlier times, I doubt we have any idea what forces were dominating. The quantum mechanics theorists take over because we are extrapolating expansion backward towards a point, and they are the ones who think they understand things when they are smaller than what we normally experience.

But, even in the temporal interface between astronomy and quantum cosmology, do we really understand what was happening? Why could dark matter not have started making mass clumps of regular matter far earlier? And, how do we know that there were not small black holes created by the Big Bang that have become the seeds for the galaxies we see today? Some are studying that, but with what physical rules for dark matter? See https://www.sciencedaily.com/releases/2022/08/220810210334.htm .
 
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Presumably this dark matter will still be around, when it comes to star formation? In particular, DM must help provide something to contain SN vibrations?
DM is definitely incorporated in today's BBT.

DM, unlike DE, is something that is now observed and associated at, if not all, galaxies. I met one astronomer, during his imaging at McDonald, who was studying DM around dwarf galaxies. He wanted to know the mass ratios for DM as a function of galaxy sizes. [It was predicted to be different than larger galaxies.]

As you note, we can, so far, only observe its gravitational effects, but such observations remove the suppositional qualification for it. It's real enough for science. :)

[DM was discovered by Zwicky in the 20's, IIRC. He observed that galaxies in a cluster were moving to fast for just the mass of the galaxies. He assumed there was much more additional matter that was unobservable, hence he coined it dark matter. I think it was Vera Rubin who put DM on the map when she revealed the non-Keplerian motion of the stars moving around Andromeda galaxy. The study of the Bullet Cluster was also a major eye-opener to DM.]

Hooper's book is quite interesting in addressing DM and the particle physicists' efforts to hunt it down. [I never knew prior to reading his book that the weak force had bias.]
 
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All this hypothesizing about how dark matter behaves seems awfully speculative, since we believe that it doesn't interact with normal matter except by gravitational attraction.
Direct evidence is always better than indirect, but DM, like black holes, has strong indirect evidence supporting it. [See above post.]

So, is it the same temperature as the normal matter? If assumed so, why? How would energy transfer between it and normal matter?
Good question. Perhaps knowing the temp. would help explain its non-uniform distribution around and in a galaxy.

Does it have "black matter pressure" by interacting with itself, or can it collapse by gravity without any regard to temperature of itself, not to mention the matter around it? Whatever you think, why do you think that?
Yeah, that might qualify for a Nobel if determined. Hooper notes that a DM particle (e.g. WIMP) will have a counter particle that would annihilate each other upon contact. Oddly, he never calls it an anti-particle though he had been using that term for all other particles upon their creation.

It seems some theorists are eager to postulate things that make their theories seem plausible, while not pursuing the related concepts that could derail their theories.
Hooper notes there are several thousand papers on DM. :) I know there are dozens on DE, though we know essentially nothing about it. But to be a theory, it must be falsifiable. If a theory can't be tested then it's metaphysics at best.

We are to the point of inferring about 95% of the matter/energy in the universe is things that we do not understand and that do not follow the rules of the 5% that we do understand.
Agreed, but we seem to be doing okay with that 5%. :)

Yet, we keep applying those rules to the other 95% whenever we don't have proof that they don't apply. Not logical.
I doubt there are many rules applied to DE or DM. Science takes what can be inferred, as you note, from them to see how their influence affects known phenomena. So far, neither seems to have any effect on the price of corn.

Once we get past the CBR to earlier times, I doubt we have any idea what forces were dominating. The quantum mechanics theorists take over because we are extrapolating expansion backward towards a point, and they are the ones who think they understand things when they are smaller than what we normally experience.
In those first nanoseconds, particle physics is our best way of testing ideas for those moments.
 
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In those first nanoseconds, particle physics is our best way of testing ideas for those moments.
"Best" is not necessarily "good enough".

The degree of certainty expressed by the BBT theorists seems far out of sync with the amount of uncertainty that would be expected from lack of so much basic knowledge.

I am not saying that the quantum BBT theory is wrong, just that is is far, far removed from the astronomical observations, and only related to the particle physics theorists by the astronomers' extrapolation of the red shifts backwards in time to a tiny point containing everything in the universe. So, timing, density, temperatures, etc. all get "explained" by folks who have never been able (so far) to meld their theories of the forces and structures of the quantum world with the observed world of the astronomers, which is dominated by gravity and the General Theory of Relativity. The incompatibilities are bridged by assumptions like "inflating" space at incredible velocities so that mass does not have to go through space at those velocities, which would not be allowed by General Relativity Theory. And timing seems to be "tuned" so that the theorized conditions have time to form hydrogen and helium atomic nuclei, but nothing heavier. I don't even know how they can calculate how much time it takes to form various nuclei from quarks, given that they are tearing them apart, not putting them together in their experiments. "Neutron" stars seem to be the most realistic observable conditions that even approach the densities and temperatures postulated for the universe soon after the "Big Bang". And, they are not "inflating" and seem to be able to collapse further to become black holes. So, when do they "inflate"?
 

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