2000 character limit reached
Ultra slow-roll inflation demystified (1707.05644v3)
Published 18 Jul 2017 in hep-ph, astro-ph.CO, and hep-th
Abstract: Ultra-slow-roll (USR) inflation is a new mode of inflation which corresponds to the occasions when the inflaton field must traverse an extremely flat part of the scalar potential, when the usual slow-roll (SR) fails. We investigate USR and obtain an estimate for how long it lasts, given the initial kinetic density of the inflaton. We also find that, if the initial kinetic density is small enough, USR can be avoided and the usual SR treatment is valid. This has important implications for inflection-point inflation.