Primordial Gravitational Waves and Reheating in a New Class of
  Plateau-like Inflationary Potentials
  We study a new class of inflation model parametrized by the Hubble radius,
such that $aH\propto \exp(-k\phi^n)$. These potentials are plateau-like, and
reduce to the power-law potentials in the simplest case $n=2$. We investigate
the range of model parameters that is consistent with current observational
constraints on the scalar spectral index and the tensor-to-scalar ratio. The
amplitude of primordial gravitational waves in these models is shown to be
accessible by future laser interferometers such as DECIGO. We also demonstrate
how these observables are affected by the temperature and equation of state
during reheating. We find that a large subset of this model can support
instantaneous reheating, as well as very low reheating temperatures of order a
few MeV, giving rise to interesting consequences for dark-matter production.
