Studying Cosmic Dawn using redshifted HI 21-cm signal: A brief review

TL;DR

This review summarizes current understanding of the HI 21-cm signal from cosmic dawn, discussing physical processes, observational prospects, and future experiments like the Square Kilometre Array to probe the early Universe.

Contribution

It provides a concise overview of the physics, observational techniques, and future prospects for studying the cosmic dawn through the HI 21-cm signal.

Findings

Different phases of cosmic dawn and their impact on the 21-cm signal

Effects of heating sources and radiation backgrounds on the global 21-cm signal

Upcoming measurements from SKA and other experiments will enhance understanding of the early Universe

Abstract

In this review article, we briefly outline our current understanding of the physics associated with the HI 21-cm signal from cosmic dawn. We discuss different phases of cosmic dawn as the ambient gas and the background radiations evolve with the redshift. We address the consequences of several possible heating sources and radiation background on the global 21-cm signal. We further review our present perspective of other important aspects of the HI 21-cm signal such as the power spectrum and imaging. Finally, we highlight the future key measurements of the Square Kilometre Array and other ongoing/upcoming experiments that will enlighten our understanding of the early Universe.