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arXiv · 1901.05963

Spin of Primordial Black Holes

Mehrdad Mirbabayi·Andrei Gruzinov·Jorge Noreña
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Abstract

Primordial black holes, formed from rare peaks in the primordial fluctuations $ζ$, are non-rotating at zeroth order in $ζ_{\rm rms}$. We show that the spin also vanishes at first order in $ζ_{\rm rms}$, suggesting the dimensionless spin parameter $a_{\rm rms} \sim ζ_{\rm rms}^2$. We identify one quadratic contribution to the spin by calculating (and extrapolating to the formation time) the torque on a black hole due to ambient acoustic waves. For a reasonable density of primordial black holes this implies a percent level spin parameter.

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Mehrdad Mirbabayi, Andrei Gruzinov, Jorge Noreña. 2020-05-11. Spin of Primordial Black Holes. https://doi.org/10.1088/1475-7516%2F2020%2F03%2F017

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