A gravitational-wave limit on the Chandrasekhar mass of dissipative dark matter: Constraining the abundance and mass spectrum of dark matter black holes using gravitational wave observations of binary black holes*

Dissipative dark matter models predict the formation of black holes through sufficient cooling and collapse of dark matter halos. In [1], Shandera et al. discuss the formation and expected mass distributions for such dark black holes(DBHs), and present expected event rates for dark black hole mergers that could be observed by Advanced LIGO and the Einstein Telescope for a range of dark black hole model parameters. Following the same dark atomic model and using LIGO and Virgo gravitational-wave observations of binary black-holes from GWTC-2 [2], we constrain the abundance and minimum mass of dark black holes in two cases - if GW190425 is a DBH binary or if none of the binary BHs from GWTC-2 are DBHs. Interpreting GW190425 as a dark matter black-hole binary limits the Chandrasekhar mass for dark matter to be below 1.4M_⊙ at > 99.9% confidence implying that the dark proton is heavier than 0.95 GeV. Similarly, results from GWTC-3[4] and subsolar mass searches for compact objects in data from LIGO-Virgo’s third observing run[5] can further constrain the abundance of dissipative dark matter as a function of the minimum possible mass of DBHs, and provide an insight into the mass of the dark proton.

[1] Shandera S. et al. PhysRevLett.120.241102

[2] LIGO-Virgo Collaborations: Abbott R. et al. PhysRevX.11.021053

[4] LIGO-Virgo Collaborations: Abbott R. et al. e-Print: 2111.03606 [gr-qc]

[5] LIGO-Virgo Collaborations: Abbott R. et al. e-Print: 2109.12197 [astro-ph.CO]