Can LIGO Detect Asymmetric Dark Matter?

Sulagna Bhattacharya, Basudeb Dasgupta, Ranjan Laha, Anupam Ray.


Dark matter from the galactic halo can accumulate in neutron stars and transmute them into sub-2.5 M_\odot black holes if the dark matter particles are heavy, stable, and have interactions with nucleons. We show that non-detection of gravitational waves from mergers of such low-mass black holes can constrain the interactions of asymmetric dark matter particles with nucleons. We find benchmark constraints with LIGO O3 data, viz., \sigma_{\chi n} \geq {\cal O}(10^{-47}) cm^2 for bosonic DM with m_\chi\sim PeV (or m_\chi\sim GeV, if they can Bose-condense) and \geq {\cal O}(10^{-46}) cm^2 for fermionic DM with m_\chi \sim 10^3 PeV. These bounds depend on the priors on DM parameters and on the currently uncertain binary neutron star merger rate density. However, if null-detection continues with increased exposure over the next decade, LIGO will set remarkable constraints. We find the forecasted sensitivity to heavy asymmetric dark matter to be world-leading, viz., dipping many orders of magnitude below the neutrino floor and completely testing the dark matter solution to missing pulsars in the Galactic center, and demonstrate a windfall science-case for gravitational wave detectors.

Associated Fellows