Only one of 19 joint 2022 FRB candidates has a repeat label in CHIME Catalog 2

We tested 19 fast radio burst candidates common to two fixed machine learning lists posted in 2022. We joined all 474 bursts marked as single in original CHIME Catalog 1 to Catalog 2 release 20251231. Twelve original records have a repeat label. Only one is in the joint list: FRB20190329A. Catalog 2 assigns it to FRB20180814A, a source already known to repeat in Catalog 1. Removing this record leaves 0 repeat labels among 18 candidates and 11 among 455 other records. The exact 95% interval for the candidate label fraction is 0–18.53%. The separate supervised and KNN lists also have no other positive label. The unsupervised list has one. Tests that remove uncertain source associations or the six bursts omitted from the original models give similar counts. Every positive group has two listed events before the first preprints, so this is a retrospective catalog comparison. Unequal exposure and missed bursts prevent inference about intrinsic repetition. We supply candidate facts, all source matches, event dates, exact tests, figures, source hashes, and code for offline and full-data reproduction.

fast radio bursts · CHIME · repeaters · candidate validation · catalog labels · source identity · machine learning