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Modified graviity

  1. Dec 18, 2012 #1


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    arXiv:1212.3687 (cross-list from gr-qc) [pdf, ps, other]
    Time delays across saddles as a test of modified gravity
    Joao Magueijo, Ali Mozaffari
    Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Extragalactic Astrophysics (astro-ph.CO); Earth and Planetary Astrophysics (astro-ph.EP)
    Modified gravity theories can produce strong signals in the vicinity of the saddles of the total gravitational potential. In a sub-class of these models this translates into diverging time-delays for echoes crossing the saddles. Such models arise from the possibility that gravity might be infrared divergent or confined, and if suitably designed they are very difficult to rule out. We show that Lunar Laser Ranging during an eclipse could probe the time-delay effect within meters of the saddle, thereby proving or excluding these models. Very Large Baseline Interferometry, instead, could target delays across the Jupiter-Sun saddle. Such experiments would shed light on the infrared behaviour of gravity and examine the puzzling possibility that there might be well-hidden regions of strong gravity and even singularities inside the solar system.

    Its the first i have heard about about strong regions of gravity in our solar system, have i been missinng the properties of some modified theories
  2. jcsd
  3. Dec 18, 2012 #2


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    Staff: Mentor

    By "saddle region" are they referring to the point close to the planet where its gravity begins to overwhelm the Sun's?
  4. Dec 19, 2012 #3


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