Fast Radio Bursts as Probes of Structure in 3D

​FRBs are bright, broadband, non-repeating, millisecond flashes of unknown
astronomical origin. The dispersion of these bursts by intervening plasma
can be used as a proxy for the distance to the burst, placing the 11 bursts
reported to date at 0.2<z<1. I will discuss the possibility of using
dispersion, instead of redshift, to study the large-scale structure of the
Universe in 3D. Like redshift, which is distorted by peculiar velocities,
dispersion is an imperfect proxy for distance as it is distorted by
inhomogeneities in the electron density. These dispersion-space
distortions are calculable and actually greatly enhance the signal. The
clustering signal in dispersion space could be detected in a survey of 10 000
FRBs, as is expected to be produced by the CHIME telescope over three years.

The greatest uncertainty in whether this technique will be successful is
the unknown nature of FRB sources. A new observation tells us more about
the environment of a source than ever before through the polarization and
scattering properties of a burst. More observations of this type, along
with interferometric observations that identify host galaxies, will soon
tell whether FRBs will provide an entirely new probe of the cosmos.