Researchers from the Astro Space Center of the Lebedev Physical Institute in Moscow have published a study that explores the potential of using the 21 cm hydrogen line absorption in the cosmic microwave background to probe the early universe and refine cosmological models. The team, consisting of Yu. N. Eroshenko, V. N. Lukash, E. V. Mikheeva, S. V. Pilipenko, and M. V. Tkachev, investigates how this absorption can be amplified and used to reconstruct the spectrum of cosmological perturbations on small scales.
The study focuses on the absorption of the cosmic microwave background by neutral hydrogen in the early universe, specifically in the 21 cm line. The researchers calculate how this absorption is affected by additional power in the form of a “bump” in the spectrum of cosmological density perturbations. They find that the main effect amplifying the absorption is the earlier formation of the first stars, which creates an ultraviolet radiation background. This radiation reduces the spin temperature of neutral hydrogen, thereby enhancing the absorption in the 21 cm line.
By comparing different cosmological models—both with and without a bump in the density perturbation spectrum—the researchers demonstrate that it is possible to determine the probable position of such a bump. This information can then be used to reconstruct the spectrum of cosmological perturbations on scales smaller than 1 megaparsec. The study highlights the potential of 21 cm line absorption as a sensitive tool for probing the early universe and refining our understanding of cosmological models.
The research was published in the Monthly Notices of the Royal Astronomical Society, a leading journal in the field of astronomy and astrophysics. While the study is primarily focused on cosmological research, the insights gained from understanding the early universe and the formation of the first stars can have broader implications for the energy sector. For instance, a deeper understanding of the early universe can inform models of star formation and the evolution of galaxies, which are crucial for studying the distribution and evolution of dark matter and dark energy. These, in turn, can impact our understanding of the large-scale structure of the universe and the distribution of matter, which are relevant for energy research, particularly in areas such as dark matter detection and the study of dark energy’s role in the acceleration of the universe’s expansion.
In summary, the study by Eroshenko and colleagues provides a novel approach to probing the early universe using 21 cm hydrogen line absorption. This research not only advances our understanding of cosmological models but also has potential applications in the energy sector, particularly in areas related to dark matter and dark energy research.
This article is based on research available at arXiv.