%0 Journal Article
%T Non-Gaussian Tail of the Curvature Perturbation in Stochastic Ultraslow-Roll Inflation: Implications for Primordial Black Hole Production
%A Figueroa, D. G.
%A Raatikainen, S.
%A Rasanen, S.
%A Tomberg, E.
%J Physical Review Letters
%D 2021
%V 127
%N 10
%I Amer Physical Soc
%@ 0031-9007
%G English
%F Figueroa_etal2021
%O WOS:000692791400004
%O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=4952), last updated on Mon, 13 Sep 2021 13:32:46 +0000
%X We consider quantum diffusion in ultraslow-roll (USR) inflation. Using the Delta N formalism, we present the first stochastic calculation of the probability distribution P(R) of the curvature perturbation during USR. We capture the nonlinearity of the system, solving the coupled evolution of the coarse-grained background with random kicks from the short wavelength modes, simultaneously with the mode evolution around the stochastic background. This leads to a non-Markovian process from which we determine the highly non-Gaussian tail of P(R). Studying the production of primordial black holes in a viable model, we find that stochastic effects during USR increase their abundance by a factor of similar to 10(5) compared with the Gaussian approximation.
%R 10.1103/PhysRevLett.127.101302
%U https://arxiv.org/abs/2012.06551
%U https://doi.org/10.1103/PhysRevLett.127.101302
%P 101302-7pp