A Brief Review on Primordial Black Holes as Dark Matter

Abstract

Primordial black holes (PBHs) represent a natural candidate for one of the components of the dark matter (DM) in the Universe. In this review, we shall discuss the basics of their formation, abundance and signatures. Some of their characteristic signals are examined, such as the emission of particles due to Hawking evaporation and the accretion of the surrounding matter, effects which could leave an impact in the evolution of the Universe and the formation of structures. The most relevant probes capable of constraining their masses and population are discussed.

PBH Formation from Spherically Symmetric Hydrodynamical Perturbations: A Review

“…For an interesting historical review of the dark matter candidates, we refer the reader to [2]. Regarding reviews that focus on gravitational waves applied to PBHs and the different constraints to account for dark matter, we have [3,14,15,39,[88][89][90][91]. Another interesting review with potential applications to PBHs is [92], which is focused on scenarios with deviations from radiation domination in the early Universe.…”

Black hole production of monopoles in the early universe

“…Aside from astrophysical black holes, black holes are often also a consequence of early universe dynamics such as hybrid inflation [3][4][5][6][7][8][9][10], phase transitions [11][12][13][14][15][16][17][18][19][20] or topological defects [21,22]. In fact, in many of these scenarios there are so many black holes produced that they become the dominant energy density of the entire universe [23][24][25][26][27][28][29].…”

Constraints on primordial black holes and curvature perturbations from the global 21-cm signal

“…Many DM models have been proposed and the most researched model is the weakly interacting massive particles (WIMPs) [19,20]. Up to now, no detection of WIMPs has led to renewed interest in other DM models, such as primordial black holes (PBHs) [21][22][23][24]. In particular, it has been argued that gravitational waves detected recently by LIGO and Virgo could be caused partly by the mergers of PBHs [25][26][27][28].…”