Abstract
We study a single-field inflation model in which the inflaton potential has an upward step between two slow-roll regimes by taking into account the finite width of the step. We calculate the probability distribution function (PDF) of the curvature perturbation P[ℛ] using the δN formalism. The PDF has an exponential-tail only for positive ℛ whose slope depends on the step width. We find that the tail may have a significant impact on the estimation of the primordial black hole abundance. We also show that the PDF P[ℛ] becomes highly asymmetric on a particular scale exiting the horizon before the step, at which the curvature power spectrum has a dip. This asymmetric PDF may leave an interesting signature in the large scale structure such as voids.
Original language | English |
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Article number | 021 |
Journal | Journal of Cosmology and Astroparticle Physics |
Volume | 2023 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2023 Nov 1 |
Keywords
- cosmological perturbation theory
- inflation
- primordial black holes
ASJC Scopus subject areas
- Astronomy and Astrophysics