Recently, there is a lot of news (see http://www.weibo.com/2803301701/AtOdsz2ON ) about black hole does not exist, due to Hawking's recent paper (http://arxiv.org/abs/1401.5761) .  

The credibility of Science is on the line: "Stephen Hawking’s Blunder on Black Holes Shows Danger of Listening to Scientists, Says Bachmann" http://www.newyorker.com/online/blogs/borowitzreport/2014/01/stephen-hawkings-blunder-on-black-holes-shows-danger-of-listening-to-scientists-says-bachmann.html

Here are my comments:

Stephen Hawking did NOT say that black holes do not exist. Hawking used to think balckholes are oblivious. Now he admits balckholes have perfect memory (like some other peoiple do), just like any other quantum systems. So what Hawking said is that balckholes are not forgetful.


In order for balckholes to have perfect memory (ie satisfies unitary quantum evolution), the classical GR must be wrong. The blackhole horizon in the classical GR must be modified. I believe that, in well defined quantum gravity (yet to be developed), the horizon carries degenerate states that give rise to blackhole entropy. There is no such thing as inside horizon. In other words, blackhole horizon behaves like a hardwall (with  nearly degenerate states). This picture contradicts with classical GR.

Hawking's picture for the horizon, I believe, is similar. This actually is a very old idea. See:

http://relativity.livingreviews.org/open?pubNo=lrr-2011-8&page=articlesu33.html

http://arxiv.org/abs/gr-qc/0303006

http://iopscience.iop.org/1742-6596/410/1/012137

So I think "Stephen Hawking believe that the classical General Relativity is wrong near the blackhole horizon". I think most people (not including me) believe that classical General Relativity is correct near the blackhole horizon.

I believe that the classical General Relativity is wrong, since I believe that a well defined quantum theory (including quantum gravity) has a finite UV cutoff. A finite UV cutoff is incompatible with  General Relativity principle.A finite UV cutoff is even incompatible Lorentz symmetry. A finite UV cutoff may modify our picture about the blackhole horizon, but I do not know how.

See also:

http://physics.stackexchange.com/questions/95366/why-does-stephen-hawking-say-black-holes-dont-exist/95830#95830

http://physics.stackexchange.com/questions/95823/does-stephen-hawking-believe-that-general-relativity-is-wrong