Black hole inside a larger black hole.

[George Jones]

Unless someone is inside a BH??

Look at the reply, post #6, by xantox.

 

[JohnnyBoy]

Doesn't the universe satisfy the conditions of Almanzo's postulated star cluster inside its own schwarzchild radius? If so then every black hole is within the event horizon of a larger black hole. cf

http://www.mathpages.com/home/kmath339.htm

 

[rkyeun]

The orbital velocity at the event horizon is the speed of light.
Your black hole cannot orbit inside the event horizon of the other black hole because it cannot go faster than the speed of light. It instead falls in and does not orbit.

 

[MathematicalPhysicist]

The problem with having a black hole inside a black hole is several fold.

Xantox is right, there is a problem with the horizon definition.

Worse, there is a problem with the asymptotics. The asymptotics of the interior black hole/star solution does not have minkowski space as a limit, so the very metric itself is poorly joined. In fact, it has some god awful time varying thing as an asymptote.

The problem has indeed been looked at before, and its apparently one of the most excruciatingly complex things to do numerically in all of physics. The last time I talked with someone about it (I believe the state of the art is in Germany), they're still in rarefied extremal D != 4 situations with a bunch of highly technical assumptions which would take a specialist to explain, and even then, the computer returns junk most of the time.

Any references to their work?

Excuse me bumping this thread.