The ineludible non-Gaussianity of the primordial black hole abundance

By V. D. Luca, G. Franciolini, A. Kehagias, Marco Peloso, A. Riotto, Caner Unal. Journal of Cosmology and Astroparticle Physics, 2019

167 citations recorded by the source corpus.

We study the formation of primordial black holes when they are generated by the collapse of large overdensities in the early universe. Since the density contrast is related to the comoving curvature perturbation by a nonlinear relation, the overdensity statistics is unavoidably non-Gaussian. We show that the abundance of primordial black holes at formation may not be captured by a perturbative approach which retains the first few cumulants of the non-Gaussian probability distribution. We provide two techniques to calculate the non-Gaussian abundance of primordial black holes at formation, one based on peak theory and the other on threshold statistics. Our results show that the unavoidable non-Gaussian nature of the inhomogeneities in the energy density makes it harder to generate PBHs. We provide simple (semi-)analytical expressions to calculate the non-Gaussian abundances of the primordial black holes and show that for both narrow and broad power spectra the gaussian case from threshold statistics is reproduced by increasing the amplitude of the power spectrum by a factor 𝒪(2÷ 3).

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/86583859115a76e5b808e596038e095b2822ff36

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. R. Cai
2. S. Young
3. C. Byrnes
4. I. Musco
5. Zongkuan Guo
6. Lang Liu
7. Jing Liu
8. Xing-Yu Yang

In Nuclear and High Energy Physics

1. S. Young
2. R. Cai
3. C. Byrnes
4. I. Musco
5. Zongkuan Guo
6. Lang Liu
7. Jing Liu
8. Xing-Yu Yang

Citations in the corpus

• Primordial black holes and gravitational waves from parametric amplification of curvature perturbations (2019, background): “[57, 76], it is found that nonGaussianity can affect the PBH abundance.”
• Generating PBHs and small-scale GWs in two-field models of inflation (2020, background): “It is well known that non-Gaussianity strongly affect the primordial abundance of PBHs [113–119] and the SBGW [120].”
• Primordial black hole formation and abundance: contribution from the non-linear relation between the density and curvature perturbation (2019, background): “The correlation of peaks in ζ and the density δρ/ρb was investigated in [62], concluding that “one can associate the number of rare peaks in the overdensity with the number of peaks in the curvature perturbation which are spiky enough”, validating the assumptions applied here.”