I Supermassive singularity the cause of the Big Bang?

Click For Summary
The discussion explores the concept of whether a supermassive singularity could be the cause of the Big Bang, emphasizing the differences between black hole singularities and the Big Bang singularity. Participants clarify that while both types of singularities indicate a breakdown of general relativity, they arise from different contexts and have distinct properties. The conversation shifts to the behavior of black holes, particularly regarding their temperature relative to the cosmic microwave background (CMB) and Hawking radiation, with participants debating the implications of black holes absorbing CMB radiation. The feasibility of detecting Hawking radiation from black holes is also examined, with challenges highlighted regarding the size and temperature of potential black holes. The overall consensus is that while black holes may eventually evaporate, current understanding and conditions complicate the detection of their radiation.
Space news on Phys.org
  • #32
Arman777 said:
https://arxiv.org/abs/0912.5297

Equation 1.1? In that equation, ##t# is the time after the Big Bang the the PBH forms; basically the equation is saying that the more time has elapsed since the Big Bang, the larger a PBH formed at that time would be. This is because the more massive a black hole is, the less "dense" it is (where "density" here means "the mass of the black hole divided by the volume of a Euclidean 3-sphere with a surface area equal to the black hole's horizon area"--which is not the actual physical density of the hole, since a black hole doesn't have a well-defined density, but plays the role of a density in the authors' proposed model for PBH formation).
 
  • #33
PeterDonis said:
his is because the more massive a black hole is, the less "dense" it is
I did no understand this part.
 

Similar threads

I Question about the big bang singularity
  • · Replies 13 ·
Replies
13
Views
5K
A Form of energy at time of big bang
  • · Replies 11 ·
Replies
11
Views
3K
B Big Bang Question -- How was the first matter formed?
  • · Replies 69 ·
3
Replies
69
Views
6K
I Could it be that the Big Bang had no cause?
  • · Replies 3 ·
Replies
3
Views
2K
I Inflationary vs deflationary phase of Big Bang
  • · Replies 10 ·
Replies
10
Views
3K
I Questions about the Location of the Big Bang and the Age of the Universe
  • · Replies 8 ·
Replies
8
Views
3K
I Post Big Bang Gravity
  • · Replies 11 ·
Replies
11
Views
3K
I Shouldn't the Big bang be physically impossible?
  • · Replies 25 ·
Replies
25
Views
4K
I Big Bang singularity: can we say anything about its size?
  • · Replies 2 ·
Replies
2
Views
2K
I Big Bang Singularity: Was It As "Infinitely Dense" As We Think?
  • · Replies 35 ·
2
Replies
35
Views
6K