High Scale Leptogenesis and Low Energy CP Violation

Aspects of non-resonant high scale leptogenesis (LG) associated with type I seesaw mechanism  will be discussed.
The questions of
i) how low can be the LG scale in the case of three right-handed neutrinos,
ii) how low/high can be the LG scale when the  CP violation is provided by the Dirac or Majorana phases in the PMNS neutrino mixing matrix,
iii)   how the transitions between the different flavour regimes take place, and
iv) is LG compatible with the Neutrino Option in general and in the case when the CP violation is due to the Dirac or Majorana phases in the PMNS matix,
will be addressed.