Predictability and Semiclassical Approximation at the onset of Black Hole formation

Abstract

We combine analytical and numerical techniques to study the collapse of conformally coupled massless scalar fields in semiclassical 2D dilaton gravity, with emphasis on solutions just below criticality when a black hole almost forms. We study classical information and quantum correlations. We show explicitly how recovery of information encoded in the classical initial data from the outgoing classical radiation becomes more difficult as criticality is approached. The outgoing quantum radiation consists of a positive-energy flux, which is essentially the standard Hawking radiation, followed by a negative-energy flux which ensures energy conservation and guarantees unitary evolution through strong correlations with the positive-energy Hawking radiation. As one reaches the critical solution there is a breakdown of unitarity. We show that this breakdown of predictability is intimately related to a breakdown of the semiclassical approximation.

26 pages RevTex + 8 figures in a separate postscript file

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Cited by in corpus (14)

• Critical phenomena in gravitational collapse
• Quantum information cannot be completely hidden in correlations: implications for the black-hole information paradox
• Critical phenomena in gravitational collapse (Physics Reports)
• Critical phenomena in gravitational collapse - Living Reviews
• Black Holes: Eliminating Information or Illuminating New Physics?
• Quantum corrections to critical phenomena in gravitational collapse
• Influence functional in two dimensional dilaton gravity
• Dilaton gravity with a boundary: from unitarity to black hole evaporation
• Exact solutions and critical chaos in dilaton gravity with a boundary
• Unveiling horizons in quantum critical collapse
• Quantum Critical Collapse Abhors a Naked Singularity
• Entropy of Localized States and Black Hole Evaporation
• Isentropic processes for axisymmetric Black Holes
• Vacuum-Bounded States and the Entropy of Black Hole Evaporation