Features from the non-attractor beginning of inflation
  We study the effects of the non-attractor initial conditions for the
canonical single-field inflation. The non-attractor stage can last only several
$e$-folding numbers, and should be followed by hilltop inflation. This
two-stage evolution leads to large scale suppression in the primordial power
spectrum, which is favored by recent observations. Moreover we give a detailed
calculation of primordial non-Guassianity due to the "from non-attractor to
slow-roll" transition, and find step features in the local and equilateral
shapes. We conclude that a plateau-like inflaton potential with an initial
non-attractor phase yields interesting features in both power spectrum and
bispectrum.
