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Holographic and trapped surfaces

  1. Sep 4, 2015 #1


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    This the breaktrhough by bousso, which was a student from Hawking. It sees it was accepted under peer review magazines in 2 months. You can find the versions at:

    1. arXiv:1504.07660 [pdf, other]
    Proof of a New Area Law in General Relativity
    Raphael Bousso, Netta Engelhardt
    Comments: 15 pages, 10 figures; v4: conclusion of Theorem IV.2 strengthened
    Journal-ref: Phys. Rev. D 92, 044031 (2015)
    Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th)

    2. arXiv:1504.07627 [pdf, other]
    A New Area Law in General Relativity
    Raphael Bousso, Netta Engelhardt
    Comments: 4 pages, 2 figures; v3: typos fixed
    Journal-ref: Phys. Rev. Lett. 115, 081301 (2015)
    Subjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc)

    I really think this might yield for the solutions Hawings offer. But first take these papers into consideration:


    High Energy Physics - Theory
    A Quantum Focussing Conjecture

    Raphael Bousso, Zachary Fisher, Stefan Leichenauer, and Aron C. Wall
    (Submitted on 8 Jun 2015)
    We propose a universal inequality that unifies the Bousso bound with the classical focussing theorem. Given a surface σ that need not lie on a horizon, we define a finite generalized entropy Sgen as the area of σ in Planck units, plus the von Neumann entropy of its exterior. Given a null congruence N orthogonal to σ, the rate of change of Sgen per unit area defines a quantum expansion. We conjecture that the quantum expansion cannot increase along N. This extends the notion of universal focussing to cases where quantum matter may violate the null energy condition. Integrating the conjecture yields a precise version of the Strominger-Thompson Quantum Bousso Bound. Applied to locally parallel light-rays, the conjecture implies a Quantum Null Energy Condition: a lower bound on the stress tensor in terms of the second derivative of the von Neumann entropy. We sketch a proof of this novel relation in quantum field theory.

    You can dare to identify the foliations defined by Bousso as related to mambrane paradigm. It's discussed here:


    There, you can find more links.

    But I think consciously or not, the black hole is being hologramophied with matter, and we see what happens with it.
  2. jcsd
  3. Sep 5, 2015 #2
    I record for posterity that this was MTd2's 2000th post.

    I wish I knew how to think about generalized holography. AdS/CFT was weird but one gets used to it: the physics in the AdS space, is equivalent to a different physics on its boundary.

    But these Bousso bounds are for surfaces "in the interior". Also they don't involve a dual description... In the AdS/CFT case, a focus on *part* of the interior of the AdS space, can correspond to a truncation of the dual CFT. So it might be that Bousso bounds also have a dual form, as statements about entanglement in an underlying quantum theory from which space-time emerges...

    I might even guess, that geometric symmetries of the emergent space-time, correspond to algebraic symmetries of the pre-space theory. And perhaps this could apply to the BMS group.
  4. Sep 5, 2015 #3

    Ben Niehoff

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    Hey, give Netta some credit. Authors on Hep-th papers are always listed alphabetically, unlike other fields where "first author" has some kind of meaning.
  5. Sep 5, 2015 #4


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    Why should we? Non-first authors in other fields deserve credit too.
  6. Sep 7, 2015 #5


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    She is amazing. Before becoming a theoretical physicist
    she was doing nano-surgery in high school
    http://mazur.harvard.edu/people.php?rowid=303&function=display [Broken]
    Last edited by a moderator: May 7, 2017
  7. Oct 10, 2015 #6


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    Generalized Second Law for Cosmology

    Raphael Bousso, Netta Engelhardt
    (Submitted on 7 Oct 2015)
    We conjecture a novel Generalized Second Law that can be applied in cosmology, regardless of whether an event horizon is present: the generalized entropy increases monotonically outside of certain hypersurfaces we call past Q-screens. A past Q-screen is foliated by surfaces whose generalized entropy (sum of area and entanglement entropy) is stationary along one future null direction and increasing along the other. We prove that our Generalized Second Law holds in spacetimes obeying the Quantum Focussing Conjecture. An analogous law applies to future Q-screens, which appear inside evaporating black holes and in collapsing regions.
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