This is a wrong-headed question to ask about theoretical physics. People have this idea that you can just say crazy physics things and they might be true, but that's not even close to the case. If you want to reach the level of conjecture, there are some incredibly high hurdles to pass. Your conjecture has to be consistent with both—both general relativity and quantum mechanics, probably the two most experimentally accurate and successful scientific theories in the history of the human race.

Here's a great lecture on this question of "well don't we need experiments? Is this all crazy physics conjecture?"

http://www.cornell.edu/video/nima-arkani-hamed-philosophy-of...

Black holes are the phenomena where quantum mechanics and gravity collide most intensely, and even theories of black hole physics compatible with both GR and QM are major achievements.

Edit: Although I agree the article is fairly opaque.

Does it matter? Theoretical physics is more of a game of logic rather than facts.

Edit: I apologize for being argumentative. Your question is somewhat intrinsic to the foundation of theoretical physics; given what we "know" now, what else can we logically deduce? There is no absolute answer, but that is part of the fun. :)

All of it is conjecture.

That's one way to do physics: You start with conjecture and try to find ways to prove it. (You can also do the reverse, find some unexplained thing and derive rules.)

In this case it might be millennia before we can prove it though.

You can simulate the equations [1] and debate if it matches observed objects.

http://arxiv.org/pdf/1601.00921v1.pdf