<p>Arxiv prodives Haiman 2012 paper <a href="https://arxiv.org/pdf/1203.6075.pdf" rel="nofollow noreferrer"><em>The Formation of the First Massive Black Holes</em></a>. The leading theory, based on WMAP, is that the first perturbations resulted in dark matter halos, which were the first gravitational concentrations of matter.</p>

<blockquote>
  <p>the first nonlinear objects in the universe were born inside ∼ 10^5 M⊙
  dark matter halos at redshifts of z ∼ 20−30</p>
</blockquote>

<p>The non-linear objects do not refer precisely to black holes. The key part for us:</p>

<blockquote>
  <p>[...] question of how the  first SMBHs  were  assembled. It is  worth
  emphasizing that this is an unsolved problem – indeed, it is not
  entirely clear even whether the first nonlinear objects in the
  universe were stars or black holes, and whether galaxies or their
  central black holes formed first.</p>
</blockquote>

<p>The article proceeds to tell a very wide range of theories, but the summary is - we are quite clear about simulating the early dark matter halos but we really don't know how to clearly show whether/how it led to SMBH formation.</p>

<p>I'd like to emphasize what is (maybe) obvious: SMBH requires a very concentrated gravity. We assume that a very early universe despite being dense didn't have enough gravity. All theories are generally about how density dropped far down and in what ways could it start to grow again, but now only inside the concentrations (i.e. when the gravity started to affect universe, the density was much lower that inside stars or black holes).</p>

CC BY-SA 3.0
2017-03-31T12:14:31.823Z
If it helps at all: gravity relates to the energy density _gradient_ as opposed to the density per se. For example if you're at the centre of the Earth gravitational potential is low and the energy density is high, but there's no gradient and no gravity. Ditto if you're midway between two stars.
John Duffield
CC BY-SA 3.0
2017-04-01T17:41:29.667Z
@JohnDuffield that's for Newtonian gravity, but not in GR.
Walter
CC BY-SA 3.0
2017-03-29T21:30:26.573Z
2017-03-29T21:58:41.340Z
2017-03-29T21:58:41.340Z
kubanczyk
<p>The problem of early SMBH formation arises because of the Eddington limit: accreting matter heats up, radiates, and the radiation pressure limits further accretion. The problem is particularly acute if the SMBH is spinning fast, because then the innermost stable circular orbit (ISCO), which sets the inner edge of the accretion disc, is closer to the hole and the accreting matter heats up much more before passing the event horizon. However, SMBHs may actually not spin much (as a result of randomly orientated infall events), when the formation of observed SMBHs at high redshifts are not a problem.</p>

CC BY-SA 3.0
2017-03-31T12:10:03.403Z
I think supermassive black holes don't spin at all.
John Duffield
CC BY-SA 3.0
2017-03-31T17:24:20.767Z
@JohnDuffield Think what you want, but they may spin, it's one of their properties (the others are mass and charge). If they accrete matter, they also accrete its spin (and charge), so may spin up if preferentially accreting material of the same angular-momentum orientation.
Walter
CC BY-SA 3.0
2017-04-01T16:47:39.073Z
I know that's what people say Walter. But I've read the Einstein digital papers, some of the things I see there don't square with some of the things I read in modern texts, and I find myself siding with Einstein.
John Duffield
CC BY-SA 3.0
2017-04-01T17:39:43.980Z
Einstein erred more often than you might think.
Walter
CC BY-SA 3.0
2017-03-30T19:12:32.670Z
2017-03-30T19:12:32.670Z
Walter
<p>I understand that space was compressed to a single point and that during the big bang all points within that expanded away from each other at phenomenal speeds. I also have heard that during this the universe wasn't the same everywhere, as in small quantum fluctuations that expanded to macroscopic scales. </p>

<p>Would this mean that higher density than normal areas could create massive black holes? Maybe not as big as the ones today but perhaps large enough to solve some of the problems with super massive black holes being observed in a short amount of time after the big bang</p>

<p>I am not asking "why didn't the universe turn into a singularity?" I am asking "Could the variable density afterwards create many singularities which could explain for the problems associated with super massive blackholes?".</p>

CC BY-SA 3.0
2017-03-28T17:54:50.960Z
Possible duplicate of [Why did the big bang not just produce a big black hole?](http://astronomy.stackexchange.com/questions/7863/why-did-the-big-bang-not-just-produce-a-big-black-hole)
Sir Cumference
CC BY-SA 3.0
2017-03-29T00:06:23.927Z
It's really not the same question, though it's related.  The linked question(s) are about the entire observable universe being well inside the schwarzchild radius of that much mass.  Big bang theory does raise that paradox.   This question is about after the initial expansion, were there large primordial black holes that formed during the expansion out of sufficient density, that became the centers of galaxies.   I've read an article here or there, that it's been proposed, but I don't know enough to answer the question.
userLTK
CC BY-SA 3.0
2017-03-29T15:23:59.000Z
I agree with userLTK, this question is distinctly different from the question posted by Sir Cumference.
zephyr
CC BY-SA 3.0
2017-03-29T15:47:22.737Z
A small correction of "space was compressed to a single point". I think *observable* universe was compressed to a point (nearly enough), while the universe can be regarded as "infinite" during the Big Bang as it is today.
kubanczyk
CC BY-SA 3.0
2017-03-29T16:08:38.250Z
Well, thats kind of the same thing isnt it? If you take infinite space but just decrease the amount of that space between all points, you still have an infinite plane... Just a very high density (in this case VERY high density)
Terran
<big-bang-theory><supermassive-black-hole><early-universe>
Could the big bang have created super massive black holes?
Terran
# Could the big bang have created super massive black holes?

(Asked by: username_0 on 2017-03-28)

I understand that space was compressed to a single point and that during the big bang all points within that expanded away from each other at phenomenal speeds. I also have heard that during this the universe wasn't the same everywhere, as in small quantum fluctuations that expanded to macroscopic scales.

Would this mean that higher density than normal areas could create massive black holes? Maybe not as big as the ones today but perhaps large enough to solve some of the problems with super massive black holes being observed in a short amount of time after the big bang

I am not asking "why didn't the universe turn into a singularity?" I am asking "Could the variable density afterwards create many singularities which could explain for the problems associated with super massive blackholes?".

**Tags:** big-bang-theory, supermassive-black-hole, early-universe
> **Comments:**
> **username_1**: Possible duplicate of [Why did the big bang not just produce a big black hole?](http://astronomy.stackexchange.com/questions/7863/why-did-the-big-bang-not-just-produce-a-big-black-hole)  
> **username_2**: It's really not the same question, though it's related.  The linked question(s) are about the entire observable universe being well inside the schwarzchild radius of that much mass.  Big bang theory does raise that paradox.   This question is about after the initial expansion, were there large primordial black holes that formed during the expansion out of sufficient density, that became the centers of galaxies.   I've read an article here or there, that it's been proposed, but I don't know enough to answer the question.  
> **username_3**: I agree with userLTK, this question is distinctly different from the question posted by Sir Cumference.  
> **username_4**: A small correction of "space was compressed to a single point". I think *observable* universe was compressed to a point (nearly enough), while the universe can be regarded as "infinite" during the Big Bang as it is today.  
> **username_0**: Well, thats kind of the same thing isnt it? If you take infinite space but just decrease the amount of that space between all points, you still have an infinite plane... Just a very high density (in this case VERY high density)  

---

## 2 answers

### Answer by username_4 on 2017-03-29. Score: 1 | Accepted answer

Arxiv prodives Haiman 2012 paper [*The Formation of the First Massive Black Holes*](https://arxiv.org/pdf/1203.6075.pdf). The leading theory, based on WMAP, is that the first perturbations resulted in dark matter halos, which were the first gravitational concentrations of matter.

> the first nonlinear objects in the universe were born inside ∼ 10^5 M⊙
> dark matter halos at redshifts of z ∼ 20−30

The non-linear objects do not refer precisely to black holes. The key part for us:

> [...] question of how the first SMBHs were assembled. It is worth
> emphasizing that this is an unsolved problem – indeed, it is not
> entirely clear even whether the first nonlinear objects in the
> universe were stars or black holes, and whether galaxies or their
> central black holes formed first.

The article proceeds to tell a very wide range of theories, but the summary is - we are quite clear about simulating the early dark matter halos but we really don't know how to clearly show whether/how it led to SMBH formation.

I'd like to emphasize what is (maybe) obvious: SMBH requires a very concentrated gravity. We assume that a very early universe despite being dense didn't have enough gravity. All theories are generally about how density dropped far down and in what ways could it start to grow again, but now only inside the concentrations (i.e. when the gravity started to affect universe, the density was much lower that inside stars or black holes).

> **Comments:**
> **username_5**: If it helps at all: gravity relates to the energy density _gradient_ as opposed to the density per se. For example if you're at the centre of the Earth gravitational potential is low and the energy density is high, but there's no gradient and no gravity. Ditto if you're midway between two stars.  
> **username_6**: @JohnDuffield that's for Newtonian gravity, but not in GR.  

---

### Answer by username_6 on 2017-03-30. Score: 1

The problem of early SMBH formation arises because of the Eddington limit: accreting matter heats up, radiates, and the radiation pressure limits further accretion. The problem is particularly acute if the SMBH is spinning fast, because then the innermost stable circular orbit (ISCO), which sets the inner edge of the accretion disc, is closer to the hole and the accreting matter heats up much more before passing the event horizon. However, SMBHs may actually not spin much (as a result of randomly orientated infall events), when the formation of observed SMBHs at high redshifts are not a problem.

> **Comments:**
> **username_5**: I think supermassive black holes don't spin at all.  
> **username_6**: @JohnDuffield Think what you want, but they may spin, it's one of their properties (the others are mass and charge). If they accrete matter, they also accrete its spin (and charge), so may spin up if preferentially accreting material of the same angular-momentum orientation.  
> **username_5**: I know that's what people say Walter. But I've read the Einstein digital papers, some of the things I see there don't square with some of the things I read in modern texts, and I find myself siding with Einstein.  
> **username_6**: Einstein erred more often than you might think.  

---

