Strengthening the de Sitter swampland conjecture in warm inflation
  The "de Sitter constraint" on the space of effective scalar field theories
consistent with superstring theory provides a lower bound on the slope of the
potential of a scalar field which dominates the evolution of the Universe,
e.g., a hypothetical inflaton field. Whereas models of single scalar field
inflation with a canonically normalized field do not obey this constraint, it
has been claimed recently in the literature that models of warm inflation can
be made compatible with it in the case of large dissipation. The de Sitter
constraint is known to be derived from entropy considerations. Since warm
inflation necessary involves entropy production, it becomes necessary to
determine how this entropy production will affect the constraints imposed by
the swampland conditions. Here, we generalize these entropy considerations to
the case of warm inflation and show that the condition on the slope of the
potential remains essentially unchanged and is, hence, robust even in the warm
inflation dynamics. We are then able to conclude that models of warm inflation
indeed can be made consistent with the "swampland" criteria.
