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arXiv · 2102.03610

Non-gaussianities for primordial black hole formation

Marco Taoso·Alfredo Urbano
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Abstract

We analyze primordial non-gaussianities in presence of an ultra-slow phase during the inflationary dynamics, focusing on scenarios relevant for the production of primordial black holes. We compute the three-point correlation function of comoving curvature perturbations finding that non-gaussianities are sizable, and predominantly local. In the context of threshold statistics, we analyze their impact for the abundance of primordial black holes, and their interplay with the non-gaussianities arising from the non-linear relation between density and curvature perturbations. We find that non-gaussianities significantly modify the estimate of the primordial black holes abundance obtained with the gaussian approximation. However, we show that this effect can be compensated by a small change, of a factor $2\div3$ at most, of the amplitude of the primordial power spectrum of curvature perturbations. This is obtained with a small tuning of the parameters of the inflationary model.

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Marco Taoso, Alfredo Urbano. 2021-02-06. Non-gaussianities for primordial black hole formation. https://doi.org/10.1088/1475-7516/2021/08/016

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