The CHIME Fast Radio Burst Population Does Not Track the Star Formation History of the Universe

Abstract The redshift distribution of fast radio bursts (FRBs) is not well constrained. association the Galactic FRB 200428 with young magnetar SGR 1935+2154 raises working hypothesis that sources track star formation history universe. discovery 20200120E in a globular cluster nearby galaxy M81, however, casts doubts on such an assumption. We apply Monte Carlo method developed previous work to test different models against recently released first CHIME catalog terms their distributions specific fluence, external dispersion measure (DM E ), and inferred isotropic energy. Our results clearly rule out all FRBs accumulated stars throughout describes data better but still cannot meet both DM energy criteria. seem be modeled either model invoking significant delay respect or hybrid dominant delayed population subdominant population. discuss implications this finding for source models.