Dark radiation and superheavy dark matter from black hole domination

By D. Hooper, G. Krnjaic, Samuel D. McDermott. Journal of High Energy Physics, 2019

141 citations recorded by the source corpus.

If even a relatively small number of black holes were created in the early universe, they will constitute an increasingly large fraction of the total energy density as space expands. It is thus well-motivated to consider scenarios in which the early universe included an era in which primordial black holes dominated the total energy density. Within this context, we consider Hawking radiation as a mechanism to produce both dark radiation and dark matter. If the early universe included a black hole dominated era, we find that Hawking radiation will produce dark radiation at a level ΔNeff ∼ 0.03 − 0.2 for each light and decoupled species of spin 0, 1/2, or 1. This range is well suited to relax the tension between late and early-time Hubble determinations, and is within the reach of upcoming CMB experiments. The dark matter could also originate as Hawking radiation in a black hole dominated early universe, although such dark matter candidates must be very heavy (mDM ≳ 1011 GeV) if they are to avoid exceeding the measured abundance.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/142cac4a17d31d0f279f843fa1c6cf45d9f25e8f

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Citations in the corpus

Gravitational wave constraints on the primordial black hole dominated early universe (2020, methodology): “Evaporation by Hawking radiation decreases the PBH mass according to [65, 66]”
Gravitational waves from a universe filled with primordial black holes (2020, background): “Nonetheless, various scenarios have been proposed [13–17] where ultra-light black holes are abundantly produced in the early universe, so abundantly that they might even dominate the energy budget of the universe for a transient period.”
The BAO+BBN take on the Hubble tension (2019, background): “The Hubble tension – and potentially also the σ8 tension – are only reduced with rather nontrivial assumptions, like self-interacting active neutrinos plus extra radiation [9–11], a light sterile neutrino interacting with a scalar field [12], Dark Matter and Dark Radiation particles belonging to the”