Prospects for clustering and lensing measurements with forthcoming intensity mapping and optical surveys

TL;DR

This paper assesses the future potential of combining intensity mapping and optical surveys to measure HI clustering and gravitational lensing, aiming to improve cosmological parameter constraints.

Contribution

It provides forecasts demonstrating the feasibility of high-precision measurements of HI clustering and lensing using upcoming surveys, and discusses their scientific implications.

Findings

High-precision measurements of HI clustering and lensing are feasible with upcoming surveys.

These measurements can constrain HI density, bias, and galaxy-HI correlation.

The study validates the potential of intensity mapping for cosmological studies.

Abstract

We explore the potential of using intensity mapping surveys (MeerKAT, SKA) and optical galaxy surveys (DES, LSST) to detect HI clustering and weak gravitational lensing of 21cm emission in auto- and cross-correlation. Our forecasts show that high precision measurements of the clustering and lensing signals can be made in the near future using the intensity mapping technique. Such studies can be used to test the intensity mapping method, and constrain parameters such as the HI density $\Omega_{\rm HI}$, the HI bias $b_{\rm HI}$ and the galaxy-HI correlation coefficient $r_{\rm HI-g}$.