I've had this idea in my mind how Black Holes could be connected to universe generation. It came about when I learned that the known universe would be a black hole if its mass was concentrated in the center, i.e. its size is about the same as the event horizon for such a mass.
Thinking backwards, obviously the universe at some point would have been described as a black hole by GR. Then of course spacetime expansion comes into play, that somehow makes it into not-a-black hole.
So here is the idea: What if a Big Bang is exactly what happens when matter falls into itself until the original spacetime continuum breaks? I.e. the energy of the original structure forms and gets linked into a new spacetime continuum - part of it as dark energy that expands the new spacetime, part of it as normal energy and matter.
Is there anything we know makes my idea impossible? If it were true, would there be a chance that we could combine our empirical knowledge of the Big Bang with this new empirical knowledge of gravitational waves to come up with a testable unified theory (i.e. Quantum Gravity)?
The idea that the universe is "inside" a black hole in another universe is a pretty old idea, but there have been several papers on it in recent years, such as this one [1], explained here [2], which offers a holographic origin.
> the known universe would be a black hole if its mass was concentrated in the center
The universe doesn't have a "center". The universe did have a much higher density right after the Big Bang, but it was expanding rapidly; that's why it was (and is) not a black hole.
> Is there anything we know makes my idea impossible?
Yes, the fact that it's based on a misconception about the universe's spacetime geometry. See above.
There are certainly "bounce" models being considered for what preceded the Big Bang (although they're by no means the only models being considered). But they don't work like what you are describing.
My point is that the way the universe works, i.e. spacetime expansion, inflation and acceleration (dark energy) could all be governed by processes inside a black hole's singularity - something we afaik don't have a good model yet. It's only a black hole from the reference point of the parent universe. I don't mean the old bounce model, more like bubbles around a water hose that get smaller the farther away from the source - i.e a stellar black hole creates a mini universe through its own spacetime rip.
> My point is that the way the universe works, i.e. spacetime expansion, inflation and acceleration (dark energy) could all be governed by processes inside a black hole's singularity
The singularity doesn't have an "inside". See below.
> something we afaik don't have a good model yet
The models that are being looked at get rid of the singularity altogether. They don't try to model it as being made up of internal parts.
> a stellar black hole creates a mini universe through its own spacetime rip.
Some physicists have considered models in which black holes give birth to "baby universes" (Hawking and Lee Smolin are two that come to mind). But these models don't "rip" spacetime; they remove the singularity, which in the standard classical GR model is just a spacelike surface--a moment of time--that represents a boundary of spacetime, and instead just extend the spacetime further on, into the spacetime of the new universe.
Thinking backwards, obviously the universe at some point would have been described as a black hole by GR. Then of course spacetime expansion comes into play, that somehow makes it into not-a-black hole.
So here is the idea: What if a Big Bang is exactly what happens when matter falls into itself until the original spacetime continuum breaks? I.e. the energy of the original structure forms and gets linked into a new spacetime continuum - part of it as dark energy that expands the new spacetime, part of it as normal energy and matter.
Is there anything we know makes my idea impossible? If it were true, would there be a chance that we could combine our empirical knowledge of the Big Bang with this new empirical knowledge of gravitational waves to come up with a testable unified theory (i.e. Quantum Gravity)?