2021/01/01 by Marco Taoso, Alfredo Urbano
Physics and Astronomy · #Amplitude #Astrophysics #Binary black hole #Black Holes and Theoretical Physics #Context (archaeology) #Correlation function (quantum field theory) #Cosmic microwave background #Cosmology and Gravitation Theories #Curvature #Galaxies: Formation, Evolution, Phenomena #Geometry #Gravitational wave #Inflation (cosmology) #Non-Gaussianity #Physics #Primordial black hole #Primordial fluctuations #Quantum mechanics #Spectral density #Statistical physics #Statistics #Trispectrum #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2021/08/016
29 pages, 10 figures. V2: minor changes, matches version to appear in JCAP
arxiv created 2021/07/27 · openalex publication_date 2021/08/01 · arxiv updated 2021/08/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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÷3 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.