Current status of gravitational collapse (full quantum mechanical treatment).

[arroy_0205]

We know about formation of (stellar mass) black hole under gravitational collapse in classical theory. But what is the result according to full quantum mechanical treatment? Can anybody tell? I have found one paper according to which, formation of trapping horizon can be questioned in semiclassical treatment (see arXiv:0712.1130). very recently I found another paper where even in classical theory formation of black hole has been questioned under certain conditions (see arXiv:0801.0294). I have not read the details, but I admit this type of issues depress me because if black holes do not exist, some really interesting problems in theoretical physics will go away.

 

[George Jones]

Since Matt Visser is a co-author, I have had a bit of a look at

http://arxiv.org/abs/0712.1130

The first thing that came to mind was that no journal reference is give. the second thing was: Is this related to

http://www.arxiv.org/abs/gr-qc/0609024 (Accepted for publication in Phys. Rev. D.)

Both the above papers are high speculative.

In 0712.1130, presently unknown high-energy physics slows down collapse until Hawking radiation takes over, while in gr-qc/0609024, Hawking radiation alone prevents the formation of black holes.

0712.1130 is interesting, but, because of its reliance on unknown high-energy physics, I wonder how seriously it will be taken.

gr-qc/0609024 is discussed a little in https://www.physicsforums.com/showthread.php?p=1534827#post1534827".

Why did gr-qc/0609024 make a big media splash, e.g.,

http://www.astronomy.com/asy/default.aspx?c=a&id=5715

and 0712.1130 didn't?

 

[CJames]

Obviously, from the thread he just referenced, I'm biased toward the idea of a black hold evaporating before it ever forms. I'm no physicist, so I shouldn't really have any say in the matter. It seems to make a lot of sense to me conceptually, though. If a black hole evaporates in finite time from an external viewpoint, and yet takes infinite time to collapse from an external viewpoint, I can't think of any reason this causality should be reversed from the viewpoint of an observer falling into the black hole. Either way, the evaporation takes place at the event horizon, and either way, the observer is outside the event horizon. But then again, I'm clueless. Really.

 

[CJames]

Forgot to mention that, yes, it is quite strange that one would get so much media attention, and the other wouldn't.