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Gravity, Dark Matter and Dark Energy are all one

  1. Nov 7, 2015 #1

    wolram

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    According to this paper not only is Dark Energy part of the field Dark Matter is too

    http://www.indiana.edu/~fluid/paper/HMW15.pdf

    In summary, we conclude that the dark matter and dark energy are essentially gravitational effect generated by the gravitational potential field gµν, its dual field Φµ and their nonlinear interactions. They can be regarded as the gravitational field energy caused by gµν and Φµ.

    Should we be pursuing this idea if we do not find non baryonic particles?
     
  2. jcsd
  3. Nov 7, 2015 #2

    phyzguy

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    Several models of this type have been proposed. It is easy to see how they can explain things like galaxy rotations curves, where the centroid of the dark matter and the centroid of the ordinary matter are aligned, and the dark matter and the ordinary matter are "pulling" in the same direction. However, how can they explain things like the Bullet Cluster, where the dark matter and the ordinary matter are pulling in different directions? I think they can't, and models like this must ultimately fail.
     
  4. Nov 7, 2015 #3

    Chronos

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    I blame it all on the power of association imbued by the prefix 'dark'.
     
  5. Nov 8, 2015 #4

    wolram

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    Looking for articles on the Bullet Cluster i found this

    The Bullet cluster consists of two clusters of galaxies that have penetrated each other leaving behind a slab of gas while the now seperating clusters retain matter as revealed through gravitational lensing. Assuming General Relativity (GR) to be valid the lensing measurements tell us that collisionless dark matter must be present in the separating clusters. But, it has been shown that the relative velocity of the two clusters need to be so large that the observed constellation ought to not occur in the real universe if it were described by GR, i.e. by the concordance cosmological model. Instead, it turns out that MOND-based models can readily account for the large relative velocity and the lensing signal as long as both clusters contain some hot dark matter or, alternatively, gas in cold clouds that cannot be detected. The Train Wreck cluster shows the opposite behaviour: assuming GR to be valid, the putative cold or warm dark matter has separated from the galaxies in this other collision of galaxy-clusters. The core of dark matter is evident from gravitational lensing (assuming GR to hold). This is inexplicable within GR because there is no known physical mechanism known for separating the dark matter from the galaxies as it does not dissipate like gas. In MOND-based models, the train wreck is also a challenge, but in principle it may perhaps be possible to separate the hot-dark-matter cluster core and the galaxies, and/or to obtain spurios lensing signals suggesting matter concentrations where there are none. Thus, the train wreck may, in the end, turn out to be a case supporting MOND-based models over GR-based ones.

    I must say i do not support MOND but what about the problems for the LCDM.

    http://www.scilogs.com/the-dark-mat...cluster-and-the-train-wreck-cluster-abel-520/
     
  6. Nov 8, 2015 #5

    wolram

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    Alternately there is this.

    http://iopscience.iop.org/article/1...321FDAC74109E474CE2.c4.iopscience.cld.iop.org

    To quantify how rare the bullet-cluster-like high-velocity merging systems are in the standard Λ cold dark matter (CDM) cosmology, we use a large-volume (27 h–3 Gpc3) cosmological N-body MICE simulation to calculate the distribution of infall velocities of subclusters around massive main clusters. The infall velocity distribution is given at (1-3)R200 of the main cluster (where R200 is similar to the virial radius), and thus it gives the distribution of realistic initial velocities of subclusters just before collision. These velocities can be compared with the initial velocities used by the non-cosmological hydrodynamical simulations of 1E0657-56 in the literature. The latest parameter search carried out by Mastropietro & Burkert has shown that an initial velocity of 3000 km s–1 at about 2R200 is required to explain the observed shock velocity, X-ray brightness ratio of the main and subcluster, X-ray morphology of the main cluster, and displacement of the X-ray peaks from the mass peaks. We show that such a high infall velocity at 2R200 is incompatible with the prediction of a ΛCDM model: the probability of finding 3000 km s–1 in (2-3)R200 is between 3.3 × 10–11 and 3.6 × 10–9. A lower velocity, 2000 km s–1 at 2R200, is also rare, and moreover, Mastropietro & Burkert have shown that such a low initial velocity does not reproduce the X-ray brightness ratio of the main and subcluster or morphology of the main cluster. Therefore, we conclude that the existence of 1E0657-56 is incompatible with the prediction of a ΛCDM model, unless a lower infall velocity solution for 1E0657-56 with [PLAIN]http://ej.iop.org/icons/Entities/lesssim.gif1800 [Broken] km s–1 at 2R200 is found.
     
    Last edited by a moderator: May 7, 2017
  7. Nov 10, 2015 #6

    wolram

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