2007/08/31 by Patrick Hayden, John Preskill · 2 citations
Physics and Astronomy · #hep-th #gr-qc #quant-ph
paper · pdf · doi:10.1088/1126-6708/2007/09/120
published as JHEP 0709:120,2007 · 18 pages, 2 figures. (v2): discussion of decoding complexity clarified
arxiv created 2007/09/21 · arxiv updated 2009/12/01
We study information retrieval from evaporating black holes, assuming that the internal dynamics of a black hole is unitary and rapidly mixing, and assuming that the retriever has unlimited control over the emitted Hawking radiation. If the evaporation of the black hole has already proceeded past the "half-way" point, where half of the initial entropy has been radiated away, then additional quantum information deposited in the black hole is revealed in the Hawking radiation very rapidly. Information deposited prior to the half-way point remains concealed until the half-way point, and then emerges quickly. These conclusions hold because typical local quantum circuits are efficient encoders for quantum error-correcting codes that nearly achieve the capacity of the quantum erasure channel. Our estimate of a black hole's information retention time, based on speculative dynamical assumptions, is just barely compatible with the black hole complementarity hypothesis.