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Decoupling condition for dark matter WIMP

  1. Jul 5, 2014 #1

    I am a research student in Theoretical Dark Matter Cosmology. I am currently working on the evolution of dark matter WIMP in the early universe. I am trying to understand how to derive the famous condition for dark matter decoupling,T = m/26. How do you get this condition from the Boltzmann equation?

    Any discussion or comments will be much appreciated. Thanks!
  2. jcsd
  3. Jul 5, 2014 #2


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    The calculation you seek is a standard one in most textbooks on the subject, but unfortunately it is a numerical one, so its a little bit hard to just write it down for you in such a forum.

    See the Tasi lectures on dark matter from 2008,
    figure 1 is the curve you are looking for.
  4. Jul 5, 2014 #3
    Okay, so it is a numerical solution. I had a feeling but was thinking if one can get it analytically someway. Thanks alot for the reference though. Cheers!1
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