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Excluding the Standard Model from Dark Matter?

  1. Jun 1, 2015 #1
    Usually, I like to bring up Dark Matter whenever I discuss cosmology or astronomy with someone, and whenever WIMPS (Weakly Interacting Massive Particles) are brought up, the person usually responds saying, "but there is no particle on the Standard Model that possesses all the particles of a WIMP"

    And thinking about it now, all our observations on Dark Matter are mainly observed through phenomenon that depend on gravity, such as gravitational microlensing, such is the case for the rational velocities of galaxies that were much faster than calculated too, they all depend on gravitational phenomenons.

    And considering that the Standard Model of Particle Physics has no full theory of gravity then it should logically be excluded from the game, the Standard Model in my opinion should not be considered (or at least not strongly considered) in "the quest for Dark Matter", so my question is: Is this idea logical?
  2. jcsd
  3. Jun 1, 2015 #2


    Staff: Mentor

    The Standard Model does not include gravity as an interaction; but it certainly does include particles that can be sources of gravity (all of them can, since anything with energy can be a source of gravity). So I don't understand what you want to "exclude" here. The fact that no known Standard Model particles are viable candidates for Dark Matter has nothing to do with the SM not including gravity as an interaction. It has to do with the fact that none of the known particles have the right combination of properties.
  4. Jun 1, 2015 #3


    User Avatar
    Science Advisor

    Not really, because quantum gravity isn't likely to have any measurable impact on the nature or behavior of dark matter. Quantum gravity, if it is important at all, is only important for the densest of objects (black holes and maybe neutron stars). Dark matter doesn't experience hardly any friction, so it never collapses into dense objects.

    In principle, the dark matter particle could have been a part of the standard model: neutrinos would be perfect candidates, if one or two of the three species of neutrino had enough mass. Unfortunately, they are just too light and thus both too high in temperature and comprising too little of the energy density of our universe to be a significant component of dark matter.

    In a way, the existence of dark matter is a validation of decades of work on trying to look for high-energy physics beyond the standard model. One of the major issues with all attempts to bring together the standard model into a large symmetry group predict a large number of different particles that we do not observe. Dark matter might just be our first observational evidence that some of these predicted particles exist.
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