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B Are massive gravitons what ripple when galaxies collide?

  1. Jun 29, 2016 #1
    Is a sea of massive gravitons what ripples when galaxy clusters collide?

    Accepted at APS Physical Review D:

    Massive gravitons as dark matter and gravitational waves

    Precursor:

    Bigravitons as dark matter and gravitational waves

    We consider the possibility that the massive graviton is a viable candidate of dark matter in the context of bimetric gravity. We first derive the energy-momentum tensor of the massive graviton and show that it indeed behaves as that of dark matter fluid.​
     
    Last edited: Jun 29, 2016
  2. jcsd
  3. Jun 30, 2016 #2
    Gravitons haven't been found and are only theoretical at the moment.

    As for the rest of your post, I want to say it's the fabric of spacetime that ripples, but I could be wrong and it's probably something else :p
     
  4. Jun 30, 2016 #3
    The authors have two sets of gravitons. One massive and one massless. The massive ones are the dark matter. The massless ones are the ones the gravitational waves propagate through.

    It would be the massive gravitons which ripple when galaxy clusters collide.

    There are a lot of breakthroughs with this article. One of the major ones is that I am assuming the massive gravitons are allowed to interact with the matter and with itself.

    For example, a "new dark force" isn't required for a dark matter fluid which consists of massive gravitons.

    Galactic Pile-Up May Point to Mysterious New Dark Force in the Universe

    this would require the dark matter to be able to interact with itself in a completely new an unexpected way
     
  5. Jun 30, 2016 #4

    Drakkith

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    I wouldn't call them breakthroughs until they are confirmed by observations.
     
  6. Jun 30, 2016 #5

    mfb

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    2016 Award

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    It is also ominous if you call your own publications "breakthroughs". Or do I misunderstand "I am assuming the massive gravitons are allowed to interact with the matter and with itself."?

    @KenFleming: Where do you see "ripples"?
     
  7. Jun 30, 2016 #6
    The Milky Way's dark matter halo appears to be lopsided

    the emerging picture of the dark matter halo of the Milky Way is dominantly lopsided in nature.​

    The Milky Way's halo may be lopsided due to the matter in the Milky Way moving through and displacing the massive gravitons, analogous to a submarine moving through and displacing the water.

    Offset between dark matter and ordinary matter: evidence from a sample of 38 lensing clusters of galaxies

    Our data strongly support the idea that the gravitational potential in clusters is mainly due to a non-baryonic fluid, and any exotic field in gravitational theory must resemble that of CDM fields very closely.​

    The offset could be caused by the galaxy clusters moving through and displacing the massive gravitons.
     
  8. Jun 30, 2016 #7
    Hubble Finds Ghostly Ring of Dark Matter

    Astronomers using NASA’s Hubble Space Telescope got a first-hand view of how dark matter behaves during a titanic collision between two galaxy clusters. The wreck created a ripple of dark matter, which is somewhat similar to a ripple formed in a pond when a rock hits the water. ​

    It makes more sense that there would be a ripple created in something which interacts with matter (the massive gravitons) then in something that doesn't (WIMPs).
     
  9. Jun 30, 2016 #8

    Drakkith

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    Until someone uses this theory to make predictions which are more accurate than current theory, your conclusions about which theory makes more sense are not valid. Also, most of your references do not outright support this new theory because they don't use it, so linking them isn't appropriate. Please link references which actually have something to do with the original papers or this thread will be locked.
     
  10. Jun 30, 2016 #9
    None of the articles I refer to use the notion of massive gravitons to explain the observed behaviors because all of the behaviors were observed before the notion of dark matter as massive gravitons was accepted by a journal which just occurred on June 20th.

    What should occur is what observations have there been in the past where the most correct explanation is a sea of massive gravitons that the matter moves through and displaces.

    The Milky Way's halo being lopsided is such an observation. The most correct explanation is that the matter the Milky Way consists of moves through and displaces a sea of massive gravitons, analogous to a submarine moving through and displacing the water.

    Maybe the scientists who noticed the Milky Way's halo is lopsided should have realized it was due to the Milky Way moving through and displacing a sea of massive gravitons. Even though they didn't figure it out doesn't mean it is not the correct explanation.

    Maybe the scientist who figured out the dark matter fluid consists of massive gravitons should have realized the Milky Way's halo is lopsided due to the matter in the Milky Way moving through and displacing the massive gravitons. Just because they didn’t doesn't mean it isn't the correct explanation.

    The paper was accepted June 20th. It is now June 30th. Maybe we should allow for more than 10 days for articles to be accepted which relate observations with the new notion of dark matter as massive gravitons which interact with matter.

    I realize we can not do that on this forum as that would be considered to be original thinking.
     
    Last edited: Jun 30, 2016
  11. Jun 30, 2016 #10

    PeterDonis

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    This does not mean the notion is right or that it has been established by observations. It just means the journal thought it was worth publishing as a speculation. The correct answer to the title question of this thread is "we don't know". No amount of discussion on this forum is going to change that. We'll have to wait and see what the data says.
     
  12. Jun 30, 2016 #11

    PeterDonis

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    Since the OP question cannot be answered more than it already has been, this thread is closed.
     
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