Some new games with classical GR are creative and attempts to use them for black hole information mysteries may be praised, but the final product is deeply flawed so far
Update: Jacques Distler criticizes this paper. His first complaint is a refined version of an objection I wrote below. Strominger, Hawking, Perry redefine the rules of the game and claim that the BMS symmetry transformations at the horizon aren't redundancies (like gauge symmetries in the bulk should be) but real symmetries, so states don't have to be invariant under them and one may produce new states. Jacques also believes that a certain diagonal BMS subgroup is ill-defined for an evaporating black hole. Finally, Distler agrees with my main general point as well – Hawking et al. work within local field theory where the information loss paradox was born and may be shown to be trouble. Some nonlocal twist is needed to avoid the paradoxes. Jacques insightfully says that local quantum field theory breaks down not only locally at short distances. It has to break at the very long Page time (when the black hole has reduced its entropy to 1/2) because at that time, the entanglement between the early and late Hawking radiation must start to show up.
This is a continuation of the story about the
BMS supertranslations and their relevance for the black hole mysteries.
Gross, Hawking, Witten, Strominger, Yau. Note how similar the photograph is to these images of 5+ supersymmetric heroes from different movies.
Andy Strominger was just interviewed by a writer for
Scientific American – not exactly one of the journals we still respect, to put it mildly (if I have to avoid the term "greasy šit") – about his recent work about
soft hair:
Stephen Hawking's New Black-Hole Paper, Translated: An Interview with Co-Author Andrew Strominger
Well, this title is bizarre – it's a paper by three authors and not just Stephen Hawking's and Strominger is in no way a "junior" co-author. One could in fact say that Strominger is the leader of this sub-industry and Hawking along with his old
co-author from 1978 and 1983 Perry have decided to be Strominger's grad students for a while again.
(However, one must understand that SciAm doesn't write for people who have a clue. It writes for SciAm commenters over there like "essentia" who only asks "what kind of scam is this?" and "naro10" who only says that Hawking has allegedly blamed the State of Israel for the existence of the black holes LOL. This is not what the interview is about, "naro10"! The remaining two commenters offer mushed potatoes involving negative entropy and fractals; and the claim that black holes are just neutron stars. Swines bombarded by pearls.)
But the interview is fun and Andy says lots of things nicely. Why the information loss looks terrible to the physicists (well, the word "determinism" looks too old-fashioned for the unitarity in quantum mechanics given the ability of QM to predict probabilities only but one implicitly hopes that Andy isn't
fundamentally misunderstanding something like that) but why it has seemed true at some point, anyway, why you can't escape from a black hole (because the horizon is a sphere expanding outward by the speed of light whose area just happens to be kept fixed thanks to the spacetime curvature), what the Strominger-Vafa derivation has changed, and so on.
Be sure that I agree with some 90% of what Strominger said in the text as a whole.