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I Is there an alternative theory to dark matter?

  1. Oct 28, 2017 #41
    I did read your long post with links, but none of the papers seem to be ruling out nuMSM neutrinos.

    Specifically, ~2-10keV sterile right-handed neutrinos with very small Yukawa coupling to active neutrinos. They do decay into active neutrinos, but lifetime is many orders of magnitude larger than age of the Universe. The resulting X-ray line is not expected to be easily seen. Tentative detection of 3.5 keV line might be it, though.
     
  2. Oct 28, 2017 #42
    I searched PF for the thread you alluded to regarding the Cooperstock paper; it did appear to raise some interest. I agree that it would be “implausible’ for Newtonian mechanics to differ widely from GR but the question remains open as to which is in error. There have been a few papers suggesting that Newtonian gravity can be applied successfully to spiral galaxies and give the observed profiles; please see my other reference given in post 10, Jalocha, J., Bratek, L. and Kutschera1, M. (2008). ‘Is Dark Matter Present in NGC 4736? An Iterative Spectral Method for Finding Mass Distribution in Spiral Galaxies.’ Astrophysical Journal, vol 679, pp 373–378. Though, one point of interest is that both these papers use a Bessel function.
     
  3. Oct 28, 2017 #43
    Just to remind you this comment was in response to a suggestion that dark matter distribution could be a free parameter. However, whilst I fully agree with your point that the dark matter has to be detectable by lensing or dynamics, it is not the case that all experimental data concur that there is a large discrepancy. Even some galaxy cluster studies appear to show that one does not require dark matter. Ref: Lu et al (2010). ‘Large-scale structure and dynamics of the most X-ray luminous galaxy cluster known – RX J1347−1145’. Mon. Not. R. Astron. Soc. 403, 1787–1800.
     
  4. Oct 28, 2017 #44

    ohwilleke

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    The problem wiht nuMSM neutrinos is that they are collisionless.
     
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