Functional form of the FRB delay distribution

Determine the precise functional form of the time-delay distribution between star formation and fast radio burst emission in the non-repeating FRB population.

Background

Analyses of CHIME/FRB samples generally reject a population that simply traces the cosmic star-formation history and instead favor suppressed evolution or a substantial delay between star formation and FRB production. Gaussian, log-normal, and power-law delay models can all provide acceptable fits under different samples and analysis choices. The precise delay distribution therefore remains unresolved.

References

Nevertheless, the precise functional form of the delay (Gaussian, log-normal, or power-law) remains poorly constrained, and different models can fit the data equally well depending on the sample and analysis method.

— A Brief Review on the Statistical Properties of Fast Radio Bursts  (2609.25810 - Sang et al., 22 Sep 2026) in Section 2.2.1, Summary