Early Universe massive Black Holes question

[ShadowKraz]

I've spent the past few days trying to find an answer to a question I have about the formation of massive black holes in the early Universe. It is possible that my search parameters were poorly formulated.
As I understand the issue, according to our current theories, massive black holes 'should not' have formed as early as we are detecting them. Obviously they did form otherwise the issue would not arise.
Is it possible that the density of dark matter, dark energy, or both was sufficient at some point during the early Universe to form these black holes? Or is my understanding that flawed?

 

[Vanadium 50]

How massive is massive? A ton? A moon? A galaxy?

 

[Mordred]

Our theories do allow for primordial BHs
https://arxiv.org/abs/2211.05767

 

[ShadowKraz]

How massive is massive? A ton? A moon? A galaxy?

Oops, my bad, I meant to type 'supermassive black holes', as found in the cores of most of the galaxies we have observed.

 

[ShadowKraz]

Our theories do allow for primordial BHs
https://arxiv.org/abs/2211.05767

My apologies, please see comment #4. I'll read the linked paper tonight; it looks very interesting, thank you.

 

[phinds]

Is it possible that the density of dark matter, dark energy, or both was sufficient at some point during the early Universe to form these black holes?

Why would you think that dark energy has anything to do with black holes in the early universe? The effects of dark energy at that time were negligible. Only after billions of years did it start to have any significant effect, most notably after about 7 or 8 billion years when it became a more dominant force than gravity for unbound systems.

 

[Vanadium 50]

The mechanism of formation of supermassive black holes is not understood. The effective density of such objects (ignoring the issues with even defining that) can be as low as that of air. So while the description "too much mass got into too small a space" sounds tautological, that's not a bad description.

The too much matter could be gas, stars, black holes, or dark matter in some proportion. I do not believe there is consensus about what that proportion is.

 

[phyzguy]

I think we don't know whether these earlier supermassive black holes were primordial black holes that grew, or whether "ordinary" black holes could grow at much faster rates than we think. The mean density of the universe was 1000's of times greater than today, so maybe there were mechanisms that would allow them to grow rapidly. Or maybe they were very large early stars that transitioned to black holes through direct collapse. It's ongoing research.

 

[Vanadium 50]

There are correlations between the size and properties of a galaxy's SMBH and its galactic bulge. That suggests there is some common factor in the evolution of both structures.

 

[ShadowKraz]

Why would you think that dark energy has anything to do with black holes in the early universe? The effects of dark energy at that time were negligible.

Because I hadn't found any information on that. Now I know, thank you.