Cosmology and Astrophysics Using the Post-reionization HI

TL;DR

This paper explores how post-reionization 21cm emission from neutral hydrogen can be used with SKA to improve understanding of dark energy and cosmic structures, emphasizing Indian scientific efforts.

Contribution

It highlights the potential of SKA-based HI intensity mapping and cross-correlation techniques for advancing cosmological studies, especially in constraining dark energy models.

Findings

SKA intensity mapping can tighten dark energy constraints.

Cross-correlation with Lyα forest aids in measuring BAO scale.

Indian scientists are actively contributing to this research area.

Abstract

We discuss the prospects of using the redshifted 21~cm emission from neutral hydrogen in the post-reionization epoch to study our universe. The main aim of the article is to highlight the efforts of Indian scientists in this area with the SKA in mind. It turns out that the intensity mapping surveys from SKA can be instrumental in obtaining tighter constraints on the dark energy models. Cross-correlation of the HI intensity maps with the Ly$\alpha$ forest data can also be useful in measuring the BAO scale.