> [270B solar masses] is the maximum mass of a black hole that models predict, at least for luminous accreting SMBHs.
as well as:
> The limit is only 5×10^10 M [50B solar masses] for black holes with typical properties, but can reach 2.7×10^11 M [270B solar masses] at maximal prograde spin (a = 1).
However in the chapter before, it's stated:
> New discoveries suggest that many black holes, dubbed 'stupendously large', may exceed 100 billion or even 1 trillion M.
If you assume constant density, anything becomes a black hole at certain volume. The question is: is our universe big enough to be a black hole or not.
I know this article. It's citing a bunch of speculative hypothesis by mostly this one person which relies on something super exotic called Einstein Cartan theory. I stand by my statement. I even suspect the article was written by them.
You have elsewhere in this thread objected to people providing links without giving context, so I hope you won't mind being asked to unpack this claim a little. Why is it nonsense? If, as you say, it's principally pushed by one person, who is that, and why does that argue against it?
(I'm not thinking this is too much to ask; saying it's wrong might require empirical support, but the claim that it's "nonsense" should be easier to justify.)
First of all, black holes have an interior and an exterior. Our universe only has an interior. Next, black holes have a singularity into which everything vanishes, or at least moves towards. Im our universe, everything moves away from a singularity. So if anything, it resembles a white hole more than a black hole. Also, our universe is expanding, whereas black holes shrink (unless matter falls into them, which can't happen to our universe because it has no exterior).
The interior and exterior are isolated; we have no idea if are universe has an exterior or not and, according to present theory, never will.
As another comment pointed out, in GR our "future" is a singularity which everything moves towards (so what we see as a time dimension).
"Expanding" and "contracting" depend on your coordinate system. If your rulers are shrinking, you can't tell this from space expanding.
The common factor here is you are wanting to use our reference frame (somewhere in this universe, not near a black hole) to describe things as they would be seen from other reference frames.
> [270B solar masses] is the maximum mass of a black hole that models predict, at least for luminous accreting SMBHs.
as well as:
> The limit is only 5×10^10 M [50B solar masses] for black holes with typical properties, but can reach 2.7×10^11 M [270B solar masses] at maximal prograde spin (a = 1).
However in the chapter before, it's stated:
> New discoveries suggest that many black holes, dubbed 'stupendously large', may exceed 100 billion or even 1 trillion M.