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T'Hooft video talk: Conformal Gravity - BH complementarity

  1. May 14, 2012 #1

    marcus

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    t'Hooft video talk: Conformal Gravity -- BH complementarity

    http://pirsa.org/12050061
    Conformal Gravity and Black Hole Complementarity
    Speaker(s): Gerard t'Hooft
    Date: 11/05/2012 - 4:40 pm
    Collection: Conformal Nature of the Universe

    Definitely worth watching at least some if not all of this talk. I'll try to find some published papers that relate to it. If you know of some already please post the links.
    The slides and presentation are excellent though the audio level is a bit low, so it demands careful listening.

    Imagine that nature is fundamentally conformal. Things have definite size for us only because that symmetry is broken by our adopting a flat world perspective. But suppose that reality has that basic symmetry. Then he models a black hole and compares two coordinatizations, from two different points of view.
    A. from the standpoint of Alice outside who never sees anything fall in and only sees Hawk. rad. come out.
    MH. and as witnessed by the Mad Hatter who falls in and only sees other infalling stuff and never sees anything get out.

    Then he says in his conformal setup these two views of reality SHARE THE SAME LIGHTCONE structure, the same view of causality. And he calculates that these two very different views of the same reality differ only by a GAUGE TRANSFORMATION.

    't Hooft's scheme of a BH seems radical to me in part because there is no singularity, as far as I can tell. I had to stop watching halfway thru the first time. Will look for some relevant papers and get back to it later today.

    Does anyone who has already watched the talk have comment?
     
  2. jcsd
  3. May 14, 2012 #2

    marcus

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    Re: t'Hooft video talk: Conformal Gravity -- BH complementarity

    These papers may give clues about how 't Hooft got to the ideas in his present talk. I'll copy the abstract of only the most recent one:

    arXiv:1011.0061
    The Conformal Constraint in Canonical Quantum Gravity
    Gerard 't Hooft

    arXiv:1009.0669
    Probing the small distance structure of canonical quantum gravity using the conformal group
    Gerard 't Hooft

    arXiv:0909.3426
    Quantum gravity without space-time singularities or horizons
    Gerard 't Hooft

    http://arxiv.org/abs/1011.0061
    The Conformal Constraint in Canonical Quantum Gravity
    Gerard 't Hooft
    (Submitted on 30 Oct 2010)
    Perturbative canonical quantum gravity is considered, when coupled to a renormalizable model for matter fields. It is proposed that the functional integral over the dilaton field should be disentangled from the other integrations over the metric fields. This should generate a conformally invariant theory as an intermediate result, where the conformal anomalies must be constrained to cancel out. When the residual metric is treated as a background, and if this background is taken to be flat, this leads to a novel constraint: in combination with the dilaton contributions, the matter lagrangian should have a vanishing beta function. The zeros of this beta function are isolated points in the landscape of quantum field theories, and so we arrive at a denumerable, or perhaps even finite, set of quantum theories for matter, where not only the coupling constants, but also the masses and the cosmological constant are all fixed, and computable, in terms of the Planck units.
     
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