Unitarity and the Hilbert space of quantum gravity

Abstract

Under the premises that physics is unitary and black hole evaporation is complete (no remnants, no topology change), there must exist a one-to-one correspondence between states on future null and timelike infinity and on any earlier spacelike Cauchy surface (e.g., slices preceding the formation of the hole). We show that these requirements exclude a large set of semiclassical spacetime configurations from the Hilbert space of quantum gravity. In particular, the highest entropy configurations, which account for almost all of the volume of semiclassical phase space, would not have quantum counterparts, i.e. would not correspond to allowed states in a quantum theory of gravity.

7 pages, 3 figures, revtex; minor changes in v2 (version published in Class. Quant. Grav.)

References in corpus (11)

• Large N Field Theories, String Theory and Gravity
• Microscopic Origin of the Bekenstein-Hawking Entropy
• The holographic principle
• A Covariant Entropy Conjecture
• Black Hole Entropy in M-Theory
• Holography in General Space-times
• Proof of Classical Versions of the Bousso Entropy Bound and of the Generalized Second Law
• Black hole entropy, curved space and monsters
• Spacetime topology change and black hole information
• Do subleading corrections to Bekenstein-Hawking entropy hold the key to quantum gravity?
• Zero Energy Configurations in General Relativity

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• Black Holes, AdS, and CFTs
• Excluding Black Hole Firewalls with Extreme Cosmic Censorship
• Point-like sources and the scale of quantum gravity
• Monsters, black holes and the statistical mechanics of gravity
• Black Hole Final State Conspiracies
• The Fate of Monsters in Anti-de Sitter Spacetime
• Wormhole Spaces: the Common Cause for the Black Hole Entropy-Area Law,the Holographic Principle and Quantum Entanglement
• Horizon Complementarity and Casimir Violations of the Null Energy Condition
• White holes and eternal black holes
• Entropy created when colliding particles fall into a black hole