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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Primordial black holes (PBHs) with mass $10^{16}-10^{17}$ g almost escapeconstraints from observations so could essentially contribute to dark matterdensity. Hawking evaporation of such PBHs produces with a steady rate $\gamma$-and $e^{\pm}$-radiations in MeV energy range, which can be absorbed by ordinarymatter. Simplified estimates show that a small fraction of evaporated energyhad to be absorbed by baryonic matter what can turn out to be enough to heatthe matter so it is fully ionized at the redshift $z\sim 5... 10$. The resultis found to be close to a borderline case where the effect appears, what makesit sensitive to the approximation used. In our approximation, degree of gasionization reaches 50-100% by $z\sim 5$ for PBH mass $(3...7)\times 10^{16}$ gwith their abundance corresponding to the upper limit.

Primordial black holes with mass $10^{16}-10^{17}$ g and reionization of the Universe