Fast Radio Bursts Trace Cosmic Star Formation with Little Delay

Abstract

The progenitor channels of fast radio bursts (FRBs) remain debated, with a central question being whether their cosmic rate traces star formation promptly or instead follows it with the long time-delay characteristic of compact-binary mergers. We perform a forward-modeling, hierarchical Bayesian analysis of the CHIME/FRB population, jointly fitting the catalog sample, baseband fluences, and localized host redshifts, while self-consistently incorporating the survey selection function through the injection framework. Across a range of delay-time models, the reconstructed FRB rate robustly peaks at the same redshift as the cosmic star-formation history, with a mean delay of only $0.1-0.3$ Gyr that remains consistent with a prompt, zero-delay origin at the $2σ$ level. For dominant FRB population, this finding rules out the multi-Gyr delays reported previously and interpreted as the evidence for compact binary merger origin, and instead points toward progenitor systems linked to young stellar remnants, most notably magnetars formed in core-collapse supernovae.