Threshold for primordial black holes: Dependence on the shape of the cosmological perturbations

By I. Musco. Physical Review D, 2018

244 citations recorded by the source corpus.

Primordial black holes may have formed in the radiative era of the early Universe from the collapse of large enough amplitude perturbations of the metric. These correspond to non linear energy density perturbations characterized by an amplitude larger than a certain threshold, measured when the perturbations reenter the cosmological horizon. The process of primordial black hole formation is studied here within spherical symmetry, using the gradient expansion approximation in the long wavelength limit, where the pressure gradients are small, and the initial perturbations are functions only of a time-independent curvature profile. In this regime it is possible to understand how the threshold for primordial black hole formation depends on the shape of the initial energy density profile, clarifying the relation between local and averaged measures of the perturbation amplitude. Although there is no universal threshold for primordial black hole formation, the averaged mass excess of the perturbation depends on the amplitude of the energy density peak, and it is possible to formulate a well-defined criterion to establish when a cosmological perturbation is able to form a black hole in terms of one of these two key quantities. This gives understanding of how the abundance of primordial black holes depends on the shape of the the inflationary power spectrum of cosmological perturbations.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/172fae59f8449541c513d422b5ecfeffdcd64ced

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In Astronomy and Astrophysics

1. Florian Kuhnel
2. B. Carr
3. Juan García-Bellido
4. J. Ezquiaga
5. V. Vennin
6. R. Cai
7. Zongkuan Guo
8. Lang Liu

In Nuclear and High Energy Physics

1. Florian Kuhnel
2. B. Carr
3. Juan García-Bellido
4. V. Vennin
5. J. Ezquiaga
6. R. Cai
7. Zongkuan Guo
8. Lang Liu

Citations in the corpus

• Primordial Black Holes as Dark Matter: Recent Developments (2020, background): “Note that there is a distinction between the threshold value for the density and curvature fluctuation [66] and one now has a good analytic understanding of these issues [67, 68].”
• Primordial black holes and gravitational waves from parametric amplification of curvature perturbations (2019, methodology): “7], we conrmed the nonGaussianity does not aect the mass function for the parameters we used. 4This is usually used as a representative value. In fact, it depends on the shape of the density prole [80]. 5 In fact, the calculations of PBH above are rough approximations. To get more accurate results, ”
• The exponential tail of inflationary fluctuations: consequences for primordial black holes (2019, methodology): “More realistic approaches incorporate the full realspace profile of the density contrast across the inhomogeneity, either numerically or by studying the compaction function [83–86].”
• Primordial black holes as dark matter candidates (2021, background): “Note that there is a distinction between the threshold value for the density fluctuation and the associated fluctuation in the curvature of the spatial hypersurfaces [24] and one now has a good analytic understanding of this issue [25, 26].”