Investigating the Early Universe: Insights from 21-cm Signal Studies

Research on the 21-cm signal from the dark ages offers critical insights into the early universe. According to a study submitted on ArXiv, titled "The magnitude of the dark ages 21-cm signal in the context of existing early and late time constraints on \Lambda CDM," the dark ages 21-cm signal could serve as a probe for understanding the infant universe, particularly between the formation of the Cosmic Microwave Background at redshift z approximately 1100 and the emergence of the first galaxies around z approximately 30.

This research aims to constrain the magnitude and central frequency of the 21-cm signal, asserting that the depth can be determined to better than 1 mK and the frequency to within 0.05 MHz, which is essential for refining the \Lambda CDM cosmological model.

Another study, titled "Sensitivity of the redshifted 21 cm signal from the Dark Ages to parameters of primordial magnetic fields," examines the impact of primordial magnetic fields on the thermal history of the universe during the dark ages, revealing that the 21-cm signal's profile is sensitive to these magnetic field parameters, which could help constrain them alongside other observational data.

These studies collectively enhance our understanding of cosmic evolution, the nature of dark matter, and the dynamics of the universe's expansion, as they explore the intricacies of the conditions prevalent in the early universe.