  We consider the introduction of a complex scalar field carrying a global
lepton number charge to the Standard Model and the Higgs inflation framework.
The conditions are investigated under which this model can simultaneously
ensure Higgs vacuum stability up to the Planck scale, successful inflation,
non-thermal Leptogenesis via the pendulum mechanism, and light neutrino masses.
These can be simultaneously achieved when the scalar lepton is minimally
coupled to gravity, that is, when standard Higgs inflation and reheating
proceed without the interference of the additional scalar degrees of freedom.
If the scalar lepton also has a non-minimal coupling to gravity, a multi-field
inflation scenario is induced, with interesting interplay between the
successful inflation constraints and those from vacuum stability and
Leptogenesis. The parameter region that can simultaneously achieve the above
goals is explored.
