Leptogenesis in the Universe
  Leptogenesis is a class of scenarios in which the cosmic baryon asymmetry
originates from an initial lepton asymmetry generated in the decays of heavy
sterile neutrinos in the early Universe. We explain why leptogenesis is an
appealing mechanism for baryogenesis. We review its motivations, the basic
ingredients, and describe subclasses of effects, like those of lepton flavours,
spectator processes, scatterings, finite temperature corrections, the role of
the heavier sterile neutrinos and quantum corrections. We then address
leptogenesis in supersymmetric scenarios, as well as some other popular
variations of the basic leptogenesis framework.
