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No Dark Matter or gravity modification for flat rot

  1. Oct 20, 2015 #1

    wolram

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    Is this a break though or just hot air?

    http://arxiv.org/pdf/1510.05534.pdf
    We do not claim that the Mestel (1963) disk is the answer to establishing the universality of flat rotation curves in galaxy disks; only that it has always been a telling clue that gravity does not pull the strings and is not in control in gaseous self-gravitating disks. Furthermore, we have solved the full Newtonian problem and we now know precisely how such universal rotation curves emerge in spiral galaxy disks. The resolution of this ubiquitous problem is the subject of this paper. Before we can delve into the physics of the problem, we need to correct some common misconceptions that appear in the theory of second-order differential equations and which also have made their way into the textbooks. We do so in § 2. Then, in § 3, we revisit the theory of rotating Newtonian isothermal gaseous-disk equilibrium models and we calculate analytically the mean shapes of their density profiles and their rotation curves. The results match precisely the shapes of the rotation curves of spiral galaxy disks with no additional assumptions of any kind. So these results make a strong case against both dark matter and modified gravity and their implications have far-reaching consequences
     
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  3. Oct 20, 2015 #2

    marcus

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    Dearly Missed

    Kazanas has a pretty good track record for publications/citations. It is not apt to be complete hot air.
    The other guy is younger, has been a frequent co-author.

    They are allowing for pressure in a rotating gaseous disk. This might help explain SOME of the flatness of the rotation curves. But Dark Matter comes in at several different scales besides spiral galaxy rotation. What they say is not so consequential. It is interesting but does not change the overall picture AFAICS.
     
  4. Oct 20, 2015 #3

    Chronos

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    A it is certainly an interesting paper and may also help explain some apparent dark matter distribution anomalies - like the core cusp problem. Another paper today; http://arxiv.org/abs/1510.05150, Dynamical measurement of the stellar surface density of face-on galaxies, highlights another such curiousity. It will be very interesting to see how the op paper is received by the community at large. I expect it will draw considerable interest. I agree with marcus in that it does not appear sufficient to explain away dark matter under all circumstances. The bullet cluster still looks pretty compelling and the dark matter fraction suggested by CMB data also looks strong. On the other hand, could it be, as the authors suggest, dark matter searches may turn out to be a modern day aether hunt?
     
  5. Oct 20, 2015 #4
    I don't think in my honest opinion that this passes the sniff test, but I will give it a look. My prime criticism is if this flattens the H I rotation curves of the gas disk why then would stellar rotation also be flat? Stars essentially don't feel pressure. Then there are also problems of galaxy-galaxy lensing and so on.
     
  6. Oct 21, 2015 #5

    wolram

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    Do you guys not think that each type of galaxy has a different history and different laws for rotation curves?
     
  7. Oct 21, 2015 #6

    Chronos

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    No, but, it lappears entirely plausible that different dynamics could affect their rotation curves.
     
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