Constraints on Singular Evolution from Gravitational Baryogenesis
  We investigate how the gravitational baryogenesis mechanism can potentially
constrain the form of a Type IV singularity. Specifically, we study two
different models with interesting phenomenology, that realize two distinct Type
IV singularities, one occurring at the end of inflation and one during the
radiation domination era or during the matter domination era. As we
demonstrate, the Type IV singularities occurring at the matter domination era
or during the radiation domination era, are constrained by the gravitational
baryogenesis, in such a way so that these do not render the baryon to entropy
ratio singular. Both the cosmological models we study cannot be realized in the
context of ordinary Einstein-Hilbert gravity, and hence our work can only be
realized in the context of $F(R)$ gravity and more generally in the context of
modified gravity only.
