[lutusp]

> If I understand correctly, black holes do not play a large role in our model of the origins of the universe. So this doesn't (directly) lead to "rethinking the origins of the universe".

But it does, because one hypothesis about the Big Bang is that it commenced from conditions identical to a black hole's singularity. So our understanding of black holes is critical to at least one idea about the universe's beginnings.

> Or does this just make us question whether that massive thing is in fact a black hole?

The answer is that there is something like a black hole at the center of our galaxy, but people are free to theorize about what exactly it is.

[wuliwong]

I disagree completely. This calculation is about the formation of a black hole from a collapsing star. There is no theory stating that the singularity of which the big bang is theorized to expand from was brought into existence from a collapsing star.

Any theory about causes of that initial singularity are basically just conjecture at this point. My understand is that some of these high dimensional theories of quantum gravity postulate colliding 'membranes' and things but they are still very much in development and this calculation does nothing to further those theories along.

Another way I was thinking about it is that the initial singularity and creation of the universe is probably more a result of large scale, topological dynamics where this paper is concerned with more local, geometric dynamics. That's my own conjecture, there. :)

[lutusp]

> There is no theory stating that the singularity of which the big bang is theorized to expand from was brought into existence from a collapsing star.

Not an issue, only that a singularity can exist, and therefore might come into being in the present.

If in a consistent physical theory we grant the reality of a singularity arising from very high matter density, then this narrows the range of possibilities for their nonexistence in the present.

So we have conventional densities easily explained by current theory, and we have the possibility of a singularity as an endpoint of increasing matter density, which narrows the discussion to the means whereby a mass might collapse past the critical density. I'm just saying this increases the burden on those who try to argue that the transition isn't possible. Especially given the absence of evidence in favor of, and plenty of evidence against, the stated thesis.