Looking at this link, CMB Anisotropy, I have two questions regarding the possible creation and properties of dark matter:
If dark matter has left it's imprint on the CMB, that to me, would imply that it was created during the time between the Big Bang and the time of recombination that we see reflected in the CMB.
Are there any papers in the literature proposing a possible mechanism whereby all of the dark matter we that postulate currently exists in the universe was created during that epoch?
That this second question is highly speculative I fully admit. Are there any papers suggesting that, a) as dark matter does not fit into the standard model, as far as I know, and b) because the Big Bang had potentially sufficient energy to create so far unknown particles, that dark matter may be indicative of the possible existence of a fourth generation of particles?