Ozsoy, Ogan, Parameswaran, Susha, Tasinato, Gianmassimo and Zavala, Ivonne
(2018)
Mechanisms for primordial black hole production in string theory.
Journal of Cosmology and Astroparticle Physics, 2018 (July).
005-005.
Text
1803.07626.pdf - Author Accepted Manuscript Download (1MB) |
Abstract
We consider mechanisms for producing a significant population of primordial black holes (PBHs) within string inspired single field models of inflation. The production of PBHs requires a large amplification in the power spectrum of curvature perturbations between scales associated with CMB and PBH formation. In principle, this can be achieved by temporarily breaking the slow-roll conditions during inflation. In this work, we identify two string setups that can realise this process. In string axion models of inflation, subleading non-perturbative effects can superimpose steep cliffs and gentle plateaus onto the leading axion potential. The cliffs can momentarily violate the slow-roll conditions, and the plateaus can lead to phases of ultra slow-roll inflation. We thus achieve a string motivated model which both matches the Planck observations at CMB scales and produces a population of light PBHs, which can account for an order one fraction of dark matter. In DBI models of inflation, a sharp increase in the speed of sound sourced by a steep downward step in the warp factor can drive the amplification. In this scenario, discovery of PBHs could indicate non-trivial dynamics in the bulk, such as flux-antibrane annihilation at the tip of a warped throat.
Item Type: | Article |
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Uncontrolled Keywords: | inflation, primordial black holes, string theory and cosmology, axions |
Depositing User: | Symplectic Admin |
Date Deposited: | 10 Dec 2018 11:18 |
Last Modified: | 19 Jan 2023 01:09 |
DOI: | 10.1088/1475-7516/2018/07/005 |
Related URLs: | |
URI: | https://livrepository.liverpool.ac.uk/id/eprint/3029655 |