21 cm Line Astronomy and Constraining New Physics

TL;DR

The paper discusses how the 21 cm signal from hydrogen during cosmic dawn can be used to detect or constrain exotic energy sources affecting the intergalactic medium, offering insights into new physics.

Contribution

It highlights the potential of the 21 cm signal to place bounds on exotic energy injections into the IGM during cosmic dawn, advancing methods to probe new physics.

Findings

21 cm signal can constrain exotic energy sources

Energy injection modifies the 21 cm absorption amplitude

Method provides robust bounds on new physics

Abstract

The 21 cm signal appears to be a treasure trove to provide an insight into the period when the first generation of luminous objects formed in the Universe. Hydrogen is the predominating fraction of the total baryonic matter during cosmic dawn (CD). Therefore, it is convenient and advantageous to study physics during CD using the 21 cm signal. The presence of any exotic source of energy can inject energy into the intergalactic medium (IGM) and heat the gas. Subsequently, it can modify the absorption amplitude in the global 21 cm signal. This feature can provide a robust bound on such sources of energy injection into the IGM gas.