CERN Accelerating science

TH institute on black hole horizons and quantum information

In classical General Relativity, black holes are the generic endpoint of gravitational collapse. They are characterized by an event horizon separating two causally disconnected regions, one visible to an asymptotic observer, the other accessible to an infalling observer. Semi-classical reasoning suggests that black holes decay by Hawking emission and eventually disappear. This is in potential conflict with the basic postulates of quantum mechanics, which require that information carried by the collapsing matter must be conserved. This paradox has catalyzed most of the recent progress in understanding the nature of quantum gravity, but has eluded a fully satisfactory solution so far. Recent thoughts experiments suggest that the semi-classical picture of a smooth, eventless horizon may be invalid, at least for old black holes which have radiated most of their entropy. The alternative to this semi-classical picture has been widely discussed over the last year, with no definite answer yet. The workshop focused on the implications of these thought experiments for the fundamental nature of gravity, and related issues. During the workshop leading quantum gravity experts came together and discussed these issues, with a light schedule of seminars leaving plenty of time for informal discussions.

The workshop followed the COST meeting on The biggest accelerators on space and earth, which took place at CERN on March 18-21. The annual COST program Black Holes in a Violent Universe, focuses on gravitational phenomena taking place at the highest-energies available in the cosmos and particle colliders, including in particular astrophysical black holes, gamma ray bursts and potential micro-black hole production at LHC. 

The TH-institute was organized by:

·         Alvarez-Gaume, Luis

·         Fernandez Barbon, Jose

·         Mangano, Michelangelo

·         Pioline, Boris Samuel

·         Rychkov, Vyacheslav



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