http://arxiv.org/abs/1709.07283
We present a thorough discussion of light dark matter produced via freeze-in in two-body decays A -> B DM. If A and B are quasi-degenerate, the dark matter particle has a cold spectrum even for sub-keV masses. We show this explicitly by calculating the transfer function that encodes the impact on structure formation. As examples for this setup we study extended seesaw mechanisms with a spontaneously broken global U(1) symmetry, such as the inverse seesaw. The eV-keV-scale pseudo-Goldstone dark matter particle is then naturally produced cold by the decays of the quasi-degenerate right-handed neutrinos.
S. Boulebnane, J. Heeck, A. Nguyen, et. al.
Fri, 22 Sep 17
63/75
Comments: 15 pages plus appendices, 4 figures