Mechanisms for primordial black hole production in string theory

By Ogan Özsoy, S. Parameswaran, G. Tasinato, I. Zavala. Journal of Cosmology and Astroparticle Physics, 2018

162 citations recorded by the source corpus.

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.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/bf8a25989c06315bbf4b058a700645174a308416

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. C. Byrnes
2. S. Young
3. A. Riotto
4. G. Franciolini
5. A. Kehagias
6. I. Musco
7. G. Tringas
8. I. Dalianis

In Nuclear and High Energy Physics

1. C. Byrnes
2. S. Young
3. I. Musco
4. A. Riotto
5. G. Franciolini
6. A. Kehagias
7. G. Tringas
8. I. Dalianis

Citations in the corpus

• Primordial black holes from inflation and quantum diffusion (2018, background): “20 · 10−25 Model [19] p = 1 p = −1 p = 2 p = −2 p = 3 p = −3 ∆qd(p) −4.”
• Generating PBHs and small-scale GWs in two-field models of inflation (2020, background): “This can be achieved in single-field inflation scenarios by using a local feature in the inflaton potential like a rapid change of its amplitude or a break in its first derivative [7–9], an inflection point [10–18] or a tiny bump superimposed on it [19, 20], non-trivial inflaton sound speed [21–23]1”
• Primordial black hole formation and abundance: contribution from the non-linear relation between the density and curvature perturbation (2019, background): “For example, the running mass model [11], axion inflation [12, 13], or a waterfall transition during hybrid inflation [14–16], a quartic action during inflation or a variable sound speed [17], amongst many others.”
• Primordial black holes from α-attractors (2018, background): “Critical Higgs inflation [20], simple polynomials or potentials with a radiative plateau a la Coleman-Weinberg where the inflaton is non-minimally coupled to the Ricci scalar [21, 22], fibre inflation [24] and axion models [25] inspired by string theory, supergravity [26] are examples of single fiel”