2023/03/01 by Theodoros Papanikolaou, Papanikolaou, Theodoros · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Pulsars and Gravitational Waves Research
paper · pdf · doi:10.48550/arxiv.2303.00600
openalex publication_date 2023/03/01 · openalex created_date 2023/03/03 · openalex updated_date 2026/07/28
The Hawking evaporation of ultra-light primordial black holes (PBH) dominating the early Universe before Big Bang Nucleosynthesis can potentially increase the effective number of extra neutrino species ΔNeff through the emission of dark radiation degrees of freedom alleviating in this way the H0 tension problem. Interestingly, these light PBHs can form a gas of Poisson distributed compact objects which can induce a gravitational-wave (GW) background due to second order gravitational interactions. Therefore, by considering the contribution to ΔNeff due to the production of the aforementioned GW background we revisit in this work the constraints on the relevant parameters at hand, namely the PBH mass, mPBH, the initial PBH abundance at PBH formation time, ΩPBH,f and the number of DR radiation degrees of freedom, gDR by accounting at the same time for the relevant upper bounds constraints on ΔNeff from the Planck collaboration.