GW190425 was detected by LIGO and Virgo in April 2019 with a total mass substantially higher than any known galactic double neutron star system. This raised immediate questions about whether it was a binary neutron star or a binary black hole merger, and whether exotic physics might explain the anomaly.

This paper develops a Bayesian framework to classify compact binary mergers using only gravitational wave data and applies it to GW190425. We also show that the anomalous mass of GW190425 is consistent with neutron stars that harbor asymmetric dark matter cores, and we place the first constraints on dark matter nucleon interactions from a gravitational wave event.

Published in Physical Review D (2026)