Abstract
In type-I seesaw model, the parameters for leptogenesis are tightly connected to low energy neutrino observables. Using Casas-Ibarra parametrization, it becomes apparent that leptogenesis can also depend on six additional high energy parameters. However, if leptogenesis were to occur at temperature greater than 10^{12} GeV and the heavy fermion mass spectrum is hierarchical, there is an u…