A scalar field rolling down a potential with a large initial velocity results in inflation of a finite duration. Such a scenario suppresses the scalar power on large scales improving the fit to the cosmological data. We find that the scenario leads to a hitherto unexplored situation wherein the boundary terms dominate the contributions to the scalar bispectrum over the bulk terms. We show that the consistency relation governing the non-Gaussianity parameter $f_{ _{ \rm NL}}$ is violated on large scales and that the contributions at the initial time can substantially enhance the value of $f_{ _{ \rm NL}}$.
Categories: astro-ph.CO gr-qc hep-th