vix.ing · top · new · best · stats

Constraints on primordial black holes

2020/02/29 by B. J. Carr, Bernard Carr, Kazunori Kohri +3 · 166 citations
Physics and Astronomy · #Anisotropy #Astronomy #Astrophysics #Big Bang nucleosynthesis #Binary black hole #Black Holes and Theoretical Physics #Cosmic microwave background #Cosmology and Gravitation Theories #Dark matter #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gravitational wave #LIGO #Nucleosynthesis #Physics #Planck #Primordial black hole #Stars #Structure formation #Universe #astro-ph.CO #gr-qc #hep-ph #hep-th

paper · pdf · doi:10.1088/1361-6633/ac1e31

published in Reports on Progress in Physics 84(11), 116902 (IOP Publishing) · 67 pages, 22 figures, REVTeX 4.1, updated to include papers in 2020. arXiv admin note: text overlap with arXiv:0912.5297

arxiv created 2021/05/09 · openalex publication_date 2021/11/01 · arxiv updated 2021/12/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Abstract We update the constraints on the fraction of the Universe that may have gone into primordial black holes (PBHs) over the mass range 10 −5 to 10 50 g. Those smaller than ∼10 15 g would have evaporated by now due to Hawking radiation, so their abundance at formation is constrained by the effects of evaporated particles on big bang nucleosynthesis, the cosmic microwave background (CMB), the Galactic and extragalactic γ -ray and cosmic ray backgrounds and the possible generation of stable Planck mass relics. PBHs larger than ∼10 15 g are subject to a variety of constraints associated with gravitational lensing, dynamical effects, influence on large-scale structure, accretion and gravitational waves. We discuss the constraints on both the initial collapse fraction and the current fraction of the dark matter (DM) in PBHs at each mass scale but stress that many of the constraints are associated with observational or theoretical uncertainties. We also consider indirect constraints associated with the amplitude of the primordial density fluctuations, such as second-order tensor perturbations and μ -distortions arising from the effect of acoustic reheating on the CMB, if PBHs are created from the high- σ peaks of nearly Gaussian fluctuations. Finally we discuss how the constraints are modified if the PBHs have an extended mass function, this being relevant if PBHs provide some combination of the DM, the LIGO/Virgo coalescences and the seeds for cosmic structure. Even if PBHs make a small contribution to the DM, they could play an important cosmological role and provide a unique probe of the early Universe.

Citations

Cited by

Related