Gravitational-wave limit on the Chandrasekhar mass of dark matter

We explore a new paradigm to study dissipative dark matter models using gravitational-wave observations. We consider a dark atomic model which predicts the formation of binary black holes such as GW190425 while obeying constraints from large-scale structure, and improving on the missing-satellite problem. Using LIGO and Virgo gravitational-wave data from September 12, 2015 to October 1, 2019, we show that interpreting GW190425 as a dark matter black-hole binary limits the Chandrasekhar mass for dark matter to be below 1.4 M⊙ at >99.9% confidence implying that the dark proton is heavier than 0.95 GeV, while also suggesting that the molecular energy-level spacing of dark molecules lies near 10-3 eV and constraining the cooling rate of dark matter at low temperatures.