Weak gravitational lensing with the Square Kilometre Array

TL;DR

This paper explores how the Square Kilometre Array (SKA) can revolutionize weak gravitational lensing studies in radio astronomy by addressing analysis challenges and leveraging unique radio data features.

Contribution

It proposes a framework for radio weak lensing with SKA, highlighting new techniques like polarization and intensity mapping to overcome existing challenges.

Findings

SKA can perform world-leading weak lensing surveys in radio.

Radio weak lensing offers unique tools like polarization to control intrinsic alignments.

SKA surveys will complement optical lensing efforts through cross-correlation.

Abstract

We investigate the capabilities of various stages of the SKA to perform world-leading weak gravitational lensing surveys. We outline a way forward to develop the tools needed for pursuing weak lensing in the radio band. We identify the key analysis challenges and the key pathfinder experiments that will allow us to address them in the run up to the SKA. We identify and summarize the unique and potentially very powerful aspects of radio weak lensing surveys, facilitated by the SKA, that can solve major challenges in the field of weak lensing. These include the use of polarization and rotational velocity information to control intrinsic alignments, and the new area of weak lensing using intensity mapping experiments. We show how the SKA lensing surveys will both complement and enhance corresponding efforts in the optical wavebands through cross-correlation techniques and by way of extending the reach of weak lensing to high redshift.