DBI inflation and warped black holes
Abstract
We study a possible amplification mechanism for the curvature perturbations generated during inflation by a Dirac-Born-Infeld (DBI) inflaton in the presence of a sharp feature in the warp factor. The large growth resulting in the scalar power spectrum is a consequence of the decreasing speed of sound. We obtain analytical approximate expressions for the relevant dynamical quantities both in the slow roll phase and during the transient phase which leads to the amplification. We finally compare our approximations to the exact numerical evolution and give, in such a context, the general rules for building a viable inflationary model leading to, during the subsequent radiation dominated era, an abundant primordial black holes formation.
- Publication:
-
Journal of Cosmology and Astroparticle Physics
- Pub Date:
- January 2022
- DOI:
- 10.1088/1475-7516/2022/01/051
- arXiv:
- arXiv:2110.08112
- Bibcode:
- 2022JCAP...01..051K
- Keywords:
-
- primordial black holes;
- inflation;
- General Relativity and Quantum Cosmology;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- High Energy Physics - Theory
- E-Print:
- 27 pages, 5 figures. Final version accepted for publication on JCAP