No torque mechanism studied supplies enough angular momentum for the innermost light-PBH shells around a heavy seed, so the spike core is swallowed and far less dense than a WIMP spike.
Primordial Black Holes as Dark Matter: Almost All or Almost Nothing
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
Primordial black holes (PBHs) are expected to accrete particle dark matter around them to form ultracompact minihalos (UCMHs), if the PBHs themselves are not most of the dark matter. We show that if most dark matter is a thermal relic, then the inner regions of UCMHs around PBHs are highly luminous sources of annihilation products. Flux constraints on gamma rays and neutrinos set strong abundance limits, improving previous limits by orders of magnitude. Assuming enough particle dark matter exists to form UCMHs, we find that Omega_PBH <~ 10^-4 (for m_DM c^2 ~ 100 GeV) for a vast range in PBH mass. We briefly discuss the uncertainties on our limits, including those due to the evolution of the UCMH luminosity as it annihilates.
citation-role summary
citation-polarity summary
fields
astro-ph.CO 2years
2026 2roles
method 1polarities
use method 1representative citing papers
CMB data limits the s-wave annihilation cross section of thermal dark matter particles to ≲ 10^{-30} cm³/s scaled by PBH fraction and mass for PBHs heavier than ~10^{-10} solar masses.
citing papers explorer
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The swallowed spike: the formation of light primordial black hole structures around heavy seeds
No torque mechanism studied supplies enough angular momentum for the innermost light-PBH shells around a heavy seed, so the spike core is swallowed and far less dense than a WIMP spike.
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In-depth analysis of the clustering of dark matter particles around primordial black holes. Part III: CMB constraints
CMB data limits the s-wave annihilation cross section of thermal dark matter particles to ≲ 10^{-30} cm³/s scaled by PBH fraction and mass for PBHs heavier than ~10^{-10} solar masses.