Entropy, Baryon Asymmetry and Dark Matter from Heavy Neutrino Decays

Understand

The origin of the hot phase of the early universe remains so far an unsolved puzzle.

• A viable option is entropy production through the decays of heavy Majorana neutrinos whose lifetimes determine the initial temperature.
• We show that baryogenesis and the production of dark matter are natural by-products of this mechanism.
• As is well known, the cosmological baryon asymmetry can be accounted for by leptogenesis for characteristic neutrino mass parameters.