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Entropic force correction to Newton law by Modesto and Randono

  1. Sep 2, 2010 #1

    marcus

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    The paper is impressive. I'll get the link. Here
    http://arxiv.org/abs/1003.1998

    On our 2nd quarter 2010 MIP ("most important paper") poll, I noticed that Atyy picked both of the Randono papers. It made me think about this one, that came out in March---the first quarter of 2010, so not on the latest poll.

    It turns out that except for one exception, the Modesto Randono March 2010 paper has the most citations of any Loop-and-allied quantum gravity paper this year. The two authors are listed as post-docs at Perimeter. As I recall Andy Randono just got his PhD a couple of years ago from U Texas Austin (Steven Weinberg is there, Randono's advisor was somebody else, I don't recall who.)

    This paper impresses me as kind of off-beat. Not everybody had the idea to take Verlinde's notion of "entropic force" seriously enough to get a correction to Newton law. Verlinde gave a kind of loose handwave argument which intuitively "derives" Newton law without any correction.

    But M and R made some assumptions about the underlying mechanics of the "entropic force"---using spin networks (familiar to many or most here at Beyond forum) and came up with a correction. To me this starts being more interesting than the plain vanilla Verlinde.

    So I'll put the abstract in case anyone wants to comment.

    Entropic corrections to Newton's law
    Leonardo Modesto, Andrew Randono
    7 pages, 2 color figures
    (Submitted on 9 Mar 2010)
    "It has been known for some time that there is a deep connection between thermodynamics and gravity, with perhaps the most dramatic implication that the Einstein equations can be viewed as a thermodynamic equation of state. Recently Verlinde has proposed a model for gravity with a simple statistical mechanical interpretation that is applicable in the non-relatvistic regime. After critically analyzing the construction, we present a strong consistency check of the model. Specifically, we consider two well-motivated corrections to the area-entropy relation, the log correction and the volume correction, and follow Verlinde's construction to derive corrections to Newton's law of gravitation. We show that the deviations from Newton's law stemming from the log correction have the same form as the lowest order quantum effects of perturbative quantum gravity, and the deviations stemming from the volume correction have the same form as some modified Newtonian gravity models designed to explain the anomalous galactic rotation curves."
     
    Last edited: Sep 2, 2010
  2. jcsd
  3. Sep 2, 2010 #2
    Maybe it is of interest to point out the paper http://arxiv.org/abs/1005.2996, which also considers corrections to Newton's law, with a focus on noncommutative geometry and unparticle physics. The conclusion is again that including these modifications into the entropic force picture yields corrections consistent with the results from computing the deviations directly.
     
  4. Sep 2, 2010 #3

    marcus

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    Someone in the past week, it may have been you, showed themselves considerably more alert to this business than I am. I was assuming the dark matter issues had been settled for all practical purposes, and spoke too dismissively of modified gravity, but this M&R paper also has a dark matter/modified gravity angle. Anyway this is just the sort of comment this thread is for. Thanks.

    I've been reading M&R and continue being impressed by it, so may quote some passages that seem especially clear-sighted.
     
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