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Particles in LQG

  1. Apr 8, 2014 #1
  2. jcsd
  3. Apr 8, 2014 #2

    marcus

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    Heh heh, twistor in the 2011 paper's authors you do not have a MAJOR collection of people currently doing LQG research. If you go back before 2011 you would find quite a few! E.g. Lee Smolin, Fotini Markopoulou.
    But there has been no interest in braid matter that I know of in the past 3 years.
    Your 2011 paper has been cited twice since it came out, in each case by an author without institutional affiliation and no significant LQG track record.

    My thought is that you do not need to worry about braids, you need a 2014 view of how matter might be included in Spin Foam or LQG. Here's a 2014 view, in the conclusions of Wieland's thesis:

     
  4. Apr 10, 2014 #3

    marcus

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    As I indicated, this post is a bit out of touch :biggrin: because for some years now LQG researchers have shown little or no interest in BRAID matter. What has recently been the most often cited pedagogical review (Rovelli's 2011 Zakopane lectures) discusses inclusion of matter by coloring spin network links and nodes. I don't recall any mention of braiding.

    However it's worth highlighting another idea that has come up. I'll quote a portion of the previous post:
    == http://tel.archives-ouvertes.fr/docs/00/95/24/98/PDF/diss.pdf pages 136-137==
    Inclusion of matter
    To aim at a phenomenology of loop quantum gravity [201–203], …
    ...
    (iv) The recent understanding of loop quantum gravity in terms of twistors is mirrored [205–209] by similar developments in the study of scattering amplitudes of e.g. N = 4 super Yang–Mills theory . It is tempting to say these results all point towards the same direction eventually yielding a twistorial framework for all interactions.
    ==endquote==
    Here, to be a bit more specific in case they mean something to you, are some of the references cited:

    [206] T. Adamo, M. Bullimore, L. Mason, and D. Skinner, “Scattering amplitudes and Wilson loops in twistor space,” J. Phys. A: Math. Theor. 44 (2011) 454008, arXiv:1104.2890.
    [207] J. J. Heckman and H. Verlinde, “Instantons, Twistors, and Emergent Gravity,” arXiv:1112.5210.
    [208] J. J. Heckman and H. Verlinde, “Gravity Amplitudes from a Gaussian Matrix Model,” arXiv:1112.5209.
    [209] F. Cachazo, L. Mason, and D. Skinner, “Gravity in Twistor Space and its Grassmannian Formulation.” 2012
     
    Last edited: Apr 10, 2014
  5. Apr 14, 2014 #4

    ftr

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  6. Apr 14, 2014 #5

    marcus

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    Yes! That old thread from back in 2010 still has some good stuff! For instance, Wen Zhao talking about LQG testing in relation to B-mode observation of CMB, and mentioning BICEP. He looked forward (already back in 2010) to the swirls in ancient light that we heard about in March of 2014.

    And it was noticeable already in 2010 that interest in "braid matter" was fading, so people were realizing that that had to work out other ways of building matter into LQG.

    So I like Wieland's sketch of 4 possible ways of doing that--three of which he personally finds interesting. I quoted his list back in post #2 of this thread.
     
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