Eliminating the LIGO bounds on primordial black hole dark matter
Abstract
Primordial black holes (PBHs) in the mass range -- are interesting candidates for dark matter, as they sit in a narrow window between microlensing and cosmic microwave background constraints. There are however tight constraints from the binary merger rate observed by the LIGO and Virgo experiments. In deriving these constraints, PBHs were treated as point Schwarzschild masses, while the more careful analysis in an expanding universe we present here, leads to a time-dependent mass. This implies a stricter set of conditions for a black hole binary to form and means that black holes coalesce much more quickly than was previously calculated, namely well before the LIGO/Virgo's observed mergers. The observed binaries are those coalescing within galactic halos, with a merger rate consistent with data. This reopens the possibility for dark matter in the form of LIGO-mass PBHs.
Keywords
Cite
@article{arxiv.2008.10743,
title = {Eliminating the LIGO bounds on primordial black hole dark matter},
author = {Celine Boehm and Archil Kobakhidze and Ciaran A. J. O'Hare and Zachary S. C. Picker and Mairi Sakellariadou},
journal= {arXiv preprint arXiv:2008.10743},
year = {2021}
}
Comments
formatting + structure updated, and some arguments have been extended and slightly rewritten for clarity. no changes to the physics or conclusions