English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The Hawking evaporation of ultra-light primordial black holes (PBH)dominating the early Universe before Big Bang Nucleosynthesis can potentiallyincrease the effective number of extra neutrino species $\Delta N_\mathrm{eff}$through the emission of dark radiation degrees of freedom alleviating in thisway the $H_0$ tension problem. Interestingly, these light PBHs can form a gasof Poisson distributed compact objects which can induce a gravitational-wave(GW) background due to second order gravitational interactions. Therefore, byconsidering the contribution to $\Delta N_\mathrm{eff}$ due to the productionof the aforementioned GW background we revisit in this work the constraints onthe relevant parameters at hand, namely the PBH mass, $m_\mathrm{PBH}$, theinitial PBH abundance at PBH formation time, $\Omega_\mathrm{PBH,f}$ and thenumber of DR radiation degrees of freedom, $g_\mathrm{DR}$ by accounting at thesame time for the relevant upper bounds constraints on $\Delta N_\mathrm{eff}$from the Planck collaboration.

The $H_0$ tension alleviated through ultra-light primordial black holes: an information insight through gravitational waves