What it takes to measure Reionization with Fast Radio Bursts

TL;DR

This paper demonstrates how Fast Radio Bursts can be used as cosmological probes to measure the history of Hydrogen reionization with high accuracy, using a model-independent approach.

Contribution

It introduces a FlexKnot free-form parameterization method to reconstruct reionization history from FRB data, achieving precise constraints on key parameters.

Findings

11% accuracy on CMB optical depth

4% accuracy on reionization midpoint

Effective use of 100 high-redshift FRBs

Abstract

Fast Radio Bursts (FRBs) are recently discovered extra-galactic radio transients which are now used as novel cosmological probes. We show how the Bursts' Dispersion Measure can model-independently probe the history of Hydrogen reionization. Using a FlexKnot free-form parameterization to reconstruct the reionization history we predict an 11% accuracy constraint on the CMB optical depth, and 4% accuracy on the midpoint of reionization, to be achieved with 100 FRBs originating from redshifts z>5.