Constraints on the cosmic string loop collapse fraction from Primordial Black Holes. (arXiv:1911.12658v1 [astro-ph.CO])

<a href="http://arxiv.org/find/astro-ph/1/au:+James_Turner_C/0/1/0/all/0/1">Chloe James-Turner</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Weil_D/0/1/0/all/0/1">Danton P. B. Weil</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Green_A/0/1/0/all/0/1">Anne M. Green</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Copeland_E/0/1/0/all/0/1">Edmund J. Copeland</a>

A small fraction, $f$, of cosmic string loops can collapse to form Primordial

Black Holes (PBHs). Constraints on the abundance of PBHs can therefore be used

to constrain $f$. We update these calculations, taking into account the PBH

extended mass function, and find $f < 10^{-32} (G mu/ c^2)^{-3/2}$. This is
roughly two orders of magnitude tighter than previous constraints. The
improvement from the tighter constraints on the abundance of PBHs is partly
off-set by refinements to the theoretical calculation of the cosmic string loop
formation rate.

A small fraction, $f$, of cosmic string loops can collapse to form Primordial

Black Holes (PBHs). Constraints on the abundance of PBHs can therefore be used

to constrain $f$. We update these calculations, taking into account the PBH

extended mass function, and find $f < 10^{-32} (G mu/ c^2)^{-3/2}$. This is

roughly two orders of magnitude tighter than previous constraints. The

improvement from the tighter constraints on the abundance of PBHs is partly

off-set by refinements to the theoretical calculation of the cosmic string loop

formation rate.

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