  Leptogenesis is at the heart of particle cosmology which requires physics
beyond the Standard Model. There are two possibilities of realizing
leptogenesis; thermal and non-thermal. Both are viable given the scale of
inflation and the constraint on the reheat temperature. However non-thermal
leptogenesis can leave its imprint upon cosmic micro wave background radiation.
In this paper we will discuss cosmological constraints on non-thermal
leptogenesis scenarios within supersymmetry.
