Fast Radio Bursts and the radio perspective on multi-messenger gravitational lensing

TL;DR

This paper reviews the potential of Fast Radio Bursts (FRBs) as tools for gravitational lensing studies, highlighting their detection, localization, and use in cosmological measurements like the Hubble constant.

Contribution

It provides a comprehensive overview of how FRBs can be used to detect gravitational lensing effects across different mass scales and discusses future prospects with upcoming radio interferometers.

Findings

FRBs can be localized to their host galaxies using interferometry.

Gravitational lensing of FRBs can probe lens masses from stellar to galactic scales.

Lensed FRBs have potential to measure cosmological parameters like the Hubble constant.

Abstract

Fast Radio Bursts (FRBs) are extragalactic millisecond-duration radio transients whose nature remains unknown. The advent of numerous facilities conducting dedicated FRB searches has dramatically revolutionised the field: hundreds of new bursts have been detected, and some are now known to repeat. Using interferometry, it is now possible to localise FRBs to their host galaxies, opening up new avenues for using FRBs as astrophysical probes. One promising application is studying gravitationally lensed FRBs. This review outlines the requirements for identifying a lensed FRB, taking into account their propagation effects and the importance of capturing the amplitude and phase of the signal. It also explores the different lens masses that could be probed with FRBs throughout the duration of an FRB survey, from stellar masses to individual galaxies. This highlights the unique cosmological applications of gravitationally lensed FRBs, including measurements of the Hubble constant and the compact object content of dark matter. Finally, we discuss future radio interferometers and the prospects for finding gravitationally lensed FRBs.