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Dark matter simulations with primordial black holes in the early Universe

Research areaAstronomy, Space and Earth Sciences
TitleDark matter simulations with primordial black holes in the early Universe
Publication TypeJournal Article
Publication year2020
AuthorsV Tkachev, M, V Pilipenko, S, Yepes, G
JournalMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Volume499
Number4
Pages4854-4862
Type of ArticleArticle
Keywordsgravitational waves}, methods: numerical, primordial black holes, {dark matter
Abstract

Primordial black holes (PBH) with masses of order 10-30 M-circle dot have been proposed as a possible explanation of the gravitational waves emission events recently discovered by the Laser Interferometer Gravitational-Wave Observatory (LIGO). If true, then PBHs would constitute a sizeable fraction of the dark matter component in the Universe. Using a series of cosmological N-body simulations that include both dark matter and a variable fraction of PBHs ranging from f(PBH) = 10(-4) to f(PBH) = 1, we analyse the processes of formation and disruption of gravitationally bound PBH pairs, as well as the merging of both bound and unbound pairs, and estimate the probabilities of such events. We show that they are in good agreement with the constrains to the PBH abundance obtained by the LIGO and other research groups. We find that pair stability, while being a main factor responsible for the merger rate, is significantly affected by the effects of dark matter halo formation and clustering. As a side result, we also evaluate the effects of numerical errors in the stability of bound pairs, which can be useful for future research using this methodology.

DOI10.1093/mnras/staa3103