3 papers
astro-ph.CO2025
Absorption effects in the expanding Universe: spectral transmittance functions of the intergalactic medium for distant sources
Anguohao Yang, Bohdan Novosyadlyj, Bohdan Melekh +1
We construct two self-consistent analytic approximations to the neutral hydrogen fraction, , and the helium ionization fractions, , …
astro-ph.CO2024
Impact of the cosmological expansion on spectral energy density of radiation in the intergalactic medium and once more about Olbers' paradox
Anguohao Yang, Bohdan Novosyadlyj, Gennadi Milinevsky
We analyse the impact of the expansion of the Universe on the formation of the total spectral energy density of radiation in the intergalactic medium. Assuming the same proper ther…
astro-ph.CO2023
Formation of the hydrogen line 21-cm in Dark Ages and Cosmic Dawn: dependences on cosmology and first light
Bohdan Novosyadlyj, Yurij Kulinich, Gennadi Milinevsky +1
We analyze the formation of the redshifted hyperfine structure line 21-cm of hydrogen atom in the Dark Ages, Cosmic Dawn, and Reionization epochs. The evolution of the global diffe…