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Résumé |
Although there is direct experimental evidence for the existence of black holes from the recent
measurements of gravitational waves, black holes are still mysterious objects from the theoretical point of
view. According to the seminal work of Stephen Hawking, all information about the collapsing matter that
forms a black hole is lost during the evaporation of Hawking radiation. This loss of information is in sharp
conflict with the rules of quantum mechanics.
It is also closely related to the no hair theorem of classical black holes, which states a black hole cannot carry
any other quantum numbers other than its mass, charge or its angular momentum. Hence it is mandatory to
understand in a quantum theory of gravity what are the carriers of information in a black hole and which kind
of quantum hair can be attributed to black holes.
In this talk, I will first briefly review how the quantum entropy of black holes emerges in string
theory. Furthermore I will also discuss a complementary picture for the hair of neutral Schwarzschild black
holes. This part is based on some recent developments related to asymptotic symmetries in gravity and a
particular bound state picture of black holes as a Bose-Einstein condensate of gravitons. Finally I give some
remarks on black holes as quantum computers. |
