Scientific Calendar Event



Description
Abstract. Primordial black holes, formed from rare peaks in the primordial fluctuations $\zeta$, are non-rotating at zeroth order in $\zeta_{rms}$. We show that the spin also vanishes at first order in $\zeta_{rms}$, suggesting the dimensionless spin parameter $a_{\rm rms} \sim \zeta_{rms}^2$. 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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