Light Dark Matter from Leptogenesis

Understand

We consider the implications of a shared production mechanism between the baryon asymmetry of the universe and the relic abundance of dark matter, that does not result in matching asymmetries.

• We present a simple model within a two sector leptogenesis framework, in which right handed sterile neutrinos decay out of equilibrium to both the Standard Model and the dark sector, generating an asymmetry in one and populating the other.
• This realization naturally accommodates light dark matter in the keV mass scale and above.
• Interactions in the dark sector may or may not cause the sector to thermalize, leading to interesting phenomenological implications, including hot, warm or cold thermal relic dark matter, while evading cosmological constraints.