Talks

Fast radio bursts (FRBs) are bright, broadband, non-repeating, millisecond flashes of unknown astronomical origin. The dispersion of these bursts by intervening plasma suggests that the sources of the 16 bursts reported to date= are 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 three dimensions. 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 observations that identify host galaxies, will soon tell whether FRBs will provide a new probe of structure.