What it takes to measure Reionization with Fast Radio Bursts

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.
2 pages, 2 figures. Contribution to the 2022 Cosmology session of the 56th Rencontres de Moriond, based on arXiv:2107.14242 (Heimersheim, Sartorio, Fialkov, Lorimer)