Exploring the Parameter Space of Warm-Inflation Models
  Warm inflation includes inflaton interactions with other fields throughout
the inflationary epoch instead of confining such interactions to a distinct
reheating era. Previous investigations have shown that, when certain
constraints on the dynamics of these interactions and the resultant radiation
bath are satisfied, a low-momentum-dominated dissipation coefficient $\propto
T^3/m_\chi^2$ can sustain an era of inflation compatible with CMB observations.
In this work, we extend these analyses by including the pole-dominated
dissipation term $\propto \sqrt{m_\chi T} \exp(-m_\chi/T)$. We find that, with
this enhanced dissipation, certain models, notably the quadratic hilltop
potential, perform significantly better. Specifically, we can achieve 50
e-folds of inflation and a spectral index compatible with Planck data while
requiring fewer mediator field ($O(10^4)$ for the quadratic hilltop potential)
and smaller coupling constants, opening up interesting model-building
possibilities. We also highlight the significance of the specific parametric
dependence of the dissipative coefficient which could prove useful in even
greater reduction in field content.
