Can we observe fuzzballs or firewalls?
In the fuzzball paradigm the information paradox is resolved because the black hole is replaced by an object with no horizon. One may therefore ask if observations can distinguish a traditional hole from a fuzzball. We give arguments for why the fuzzball structure should lie close to the horizon; i.e., it should be a ‘tight’ fuzzball. We find: (a) It is very difficult to reflect quanta off the surface of such a fuzzball, mainly because geodesics starting near the horizon radius cannot escape to infinity unless their starting direction is very close to radial. (b) If infalling particles interact with the emerging radiation before they are engulfed by the horizon, then we say that we have a ‘firewall behavior’. We consider several types of interactions, but find no evidence for firewall behavior in any theory that obeys causality. (c) Photons with wavelengths larger than the black hole radius can be
scattered off the emerging radiation, but a very small fraction of the backscattered photons will be able to escape back to infinity.
KeywordsBlack Holes Black Holes in String Theory Models of Quantum Gravity
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
- S.W. Hawking, Particle Creation by Black Holes, Commun. Math. Phys. 43 (1975) 199 [Erratum ibid. 46 (1976) 206] [INSPIRE].
- S.W. Hawking, Breakdown of Predictability in Gravitational Collapse, Phys. Rev. D 14 (1976) 2460 [INSPIRE].
- D. Marolf, private communication (2013).Google Scholar
- W.G. Unruh, Absorption Cross-Section of Small Black Holes, Phys. Rev. D 14 (1976) 3251 [INSPIRE].
- D.N. Page, Particle Emission Rates from a Black Hole: Massless Particles from an Uncharged, Nonrotating Hole, Phys. Rev. D 13 (1976) 198 [INSPIRE].