Article
Astronomy & Astrophysics
Krzysztof A. Meissner, Hermann Nicolai
Summary: Building on the insight that primordial black holes can arise from the formation and subsequent gravitational collapse of bound states of stable supermassive elementary particles during the early radiation era, the study offers a comprehensive picture describing the evolution and growth of the resulting mini-black holes through both the radiation and matter dominated phases. By solving Einstein's equations throughout both phases, the research shows that this process explains the observed mass values of the earliest giant black holes and predicts a lower limit on the mass of supermassive black holes.
Review
Physics, Multidisciplinary
Bernard Carr, Kazunori Kohri, Yuuiti Sendouda, Jun'ichi Yokoyama
Summary: In this article, constraints on the fraction of the Universe that may have gone into primordial black holes (PBHs) over a range of masses are updated. The discussion covers the reasons why PBHs smaller than a certain mass threshold are constrained and the various constraints on PBHs larger than that threshold.
REPORTS ON PROGRESS IN PHYSICS
(2021)
Article
Astronomy & Astrophysics
Paulo B. Ferraz, Thomas W. Kephart, Joao G. Rosa
Summary: We show that highly spinning primordial black holes can produce clouds of pions in their vicinity via the superradiant instability. The electromagnetic signatures of this process, including neutral pion decay and charged pion annihilation into photons, contribute to the isotropic gamma-ray background. This allows us to place upper bounds on the abundance of such black holes and discuss the possibility of directly observing these clouds in high-redshift superclusters.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Keisuke Inomata, Evan McDonough, Wayne Hu
Summary: Research shows that accelerating after passing through a relatively small downward step in the potential can generate primordial black holes and explain certain astronomical observations, and this perturbation enhancement may be due to particle production associated with nonadiabatic transitions.
Article
Astronomy & Astrophysics
Bao-Min Gu, Fu-Wen Shu, Ke Yang, Yu-Peng Zhang
Summary: By studying a toy inflation model with a local minimum, it is found that the curvature perturbations are enhanced when the inflaton passes through the local minimum, leading to the production of primordial black holes (PBHs) on small scales. The PBHs could potentially make up the total dark matter in the mass window of 10^16-10^20 g.
Article
Astronomy & Astrophysics
Albert Escriva, Yuichiro Tada, Shuichiro Yokoyama, Chul-Moon Yoo
Summary: In this work, numerical simulations of primordial black hole formation were performed in the presence of non-Gaussianity. Comparisons with previous analytical estimations showed discrepancies in certain cases, but an alternative direct analytical estimate was found to be more accurate in determining the critical conditions.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Trey W. Jensen, Yacine Ali-Haimoud
Summary: This study investigates the relationship between the mass product of black holes and cosmic microwave background radiation, and observes the temperature trispectrum or related four-point function through the energy injection of black holes into the recombining plasma.
Article
Astronomy & Astrophysics
K. Kritos, V De Luca, G. Franciolini, A. Kehagias, A. Riotto
Summary: This study critically assesses the formation and merging of binary systems made of a primordial black hole and a black hole of astrophysical origin in stellar clusters, aiming to reproduce the detection rate of LIGO/Virgo. A new catalysis channel based on a chain of single-binary and binary-binary exchanges is proposed to potentially explain the recent GW190521 event.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
I. J. Araya, N. D. Padilla, M. E. Rubio, J. Sureda, J. Magana, L. Osorio
Summary: We investigate the presence of electric charge in primordial black holes (PBHs) up to the present time. It is found that PBHs can possess a non-zero net charge at their formation, either due to Poisson fluctuations during horizon crossing or high-energy particle collisions. Despite rapid discharge processes such as particle accretion or quantum particle emission, PBHs with maximum rotation can generate magnetic fields that could shield them from discharge. Additionally, the plasma within virialized dark matter haloes can endow PBHs with a net negative charge, considering that electrons are the lightest and fastest charge carriers. We report charge-to-mass ratios ranging from 10-31 C/kg to 10-15 C/kg for PBHs within the mass windows allowing them to constitute the entirety of the dark matter in the Universe.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Naoya Kitajima, Yuichiro Tada, Shuichiro Yokoyama, Chul-Moon Yoo
Summary: This paper updates the peak theory for estimating the abundance of primordial black holes (PBHs) by implementing critical behavior in PBH mass estimation and using the averaged compaction function for the PBH formation criterion. The study applies the peak theory to a specific non-Gaussian feature, known as the exponential tail, which is characteristic of ultra slow-roll inflation models. The results show a significant enhancement in the PBH abundance and reveal a characteristic maximal mass in the PBH mass spectrum not seen in the simple Press-Schechter approach.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Hai-Jun Li
Summary: This paper investigates the stochastic oscillations between axion-like particles (ALPs) and photons in the cosmic magnetic field. Numerical results of ALP-photon oscillation probability distributions are presented for different magnetic field scenarios. These oscillations may have effects on phenomena such as the cosmic microwave background, the cosmic X-ray background, and the extragalactic gamma-ray background.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Volodymyr Takhistov, Philip Lu, Graciela B. Gelmini, Kohei Hayashi, Yoshiyuki Inoue, Alexander Kusenko
Summary: This study provides a detailed analysis on the various aspects of interstellar gas heating, including PBH emission mechanisms and constraints on the PBH abundance for different mass ranges. Observational data from the Leo T dwarf galaxy is used to constrain the PBH abundance relevant to intermediate-mass BHs. The study also considers PBH gas heating in systems with bulk relative velocity to the DM.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Heling Deng
Summary: In various mechanisms generating primordial black holes, each black hole is expected to form along with a surrounding underdense region. The dissipation of this region could lead to detectable mu-distortion in the CMB spectrum. Current bounds suggest the potential for detection of mu-distortion, with the possibility of stringent limitations on the population of large primordial black holes.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Marco Taoso, Alfredo Urbano
Summary: The study analyzes the impact of primordial non-gaussianities in the presence of an ultra-slow phase during inflationary dynamics, focusing on scenarios relevant for the production of primordial black holes. By computing the three-point correlation function of comoving curvature perturbations, it is found that non-gaussianities are significant and mainly local, affecting the estimated abundance of primordial black holes obtained with the Gaussian approximation. However, it is shown that this effect can be compensated by slightly adjusting the amplitude of the primordial power spectrum of curvature perturbations through a small tuning of the parameters of the inflationary model.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Chiara Animali, Vincent Vennin
Summary: In this work, we study cosmological fluctuations and the formation of Primordial Black Holes (PBHs) through the process of stochastic tunneling, where the inflaton escapes a local minimum of its potential through quantum fluctuations. We analyze two different toy models and find that when the potential barrier is small enough compared to its width, the potential can be approximated as flat and PBHs are not massively produced. However, when the potential barrier height exceeds a certain critical value, the PBH abundance grows exponentially or even super-exponentially.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)