Cosmological measurements of the 21-cm line neutral hydrogen are poised to dramatically enhance our understanding early universe. In particular, both epochs reionization and cosmic dawn remain largely uncharted, signal is one few probes reach them. Conceptually, simplest measurement global (GS), which corresponds averaged absorption or emission photons across entire sky. While bright radio fore...

Abstract Hawking radiation from primordial black holes (PBH) can ionize and heat up neutral gas during the cosmic dark ages, leaving imprints on global 21-cm signal of hydrogen. We use to constrain abundance spinning PBHs in mass range [2 × 10 13 , 18 ] grams. consider several extended PBH distribution models. Our results show that set most stringent bounds our window. Compared with constraints...