2018/12/31 by Samuel Passaglia, Wayne Hu, Hayato Motohashi · 4 citations
Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #Cosmic microwave background #Cosmology and Gravitation Theories #Curvature #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gaussian #Inflation (cosmology) #Inflaton #Non-Gaussianity #Physics #Primordial black hole #Primordial fluctuations #Quantum mechanics #Slow roll #Theoretical physics #astro-ph.CO #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.99.043536
published as Phys. Rev. D 99, 043536 (2019) · 18 pages, 8 figures; matches published version
arxiv created 2019/02/26 · openalex publication_date 2019/02/26 · arxiv updated 2019/02/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Primordial black holes (PBHs) cannot be produced abundantly enough to be the dark matter in canonical single-field inflation under slow roll. This conclusion is robust to local non-Gaussian correlations between long- and short-wavelength curvature modes, which we show have no effect in slow roll on local primordial black hole abundances. For the prototypical model which evades this no-go, ultra-slow roll (USR), these squeezed non-Gaussian correlations have at most an order-unity effect on the variance of PBH-producing curvature fluctuations for models that would otherwise fail to form sufficient PBHs. Moreover, the transition out of USR, which is necessary for a successful model, suppresses even this small enhancement unless it causes a large increase in the inflaton kinetic energy in a fraction of an e-fold, which we call a large and fast transition. Along the way we apply the in-in formalism, the \ensuremathδN formalism, and gauge transformations to compute non-Gaussianities and illuminate different aspects of the physical origin of these results. Local non-Gaussianity in the squeezed limit does not weaken the Gaussian conclusion that PBHs as dark matter in canonical single-field inflation require a complicated and fine-tuned potential shape with an epoch where slow roll is transiently violated.