Constraining mass of the WIMP dark matter with the help of Gravitational Waves posterior

In this work, we explore the likelihood of neutron star admixed with dark matter (DM) as a secondary compact component of GW190814 merger event and constrain the mass of WIMP, with the help of universality relation, and GW170817 posteriors. We have considered a relatively light neutralino, a component of weakly interacting massive particles, as a dark matter candidate which interacts with the baryonic matter of the neutron star (NS) through the exchange of Higgs boson. The baryonic part of the equations-of-state of NS is considered within the relativistic mean-field model with the IOPB-I, G3, and NL3 parameter sets. In efforts to constrain the WIMP mass, we have presumed the DM inside a neutron star core and analyzed its effects on the $M-R$ curves, and $C-\Lambda$ universality relations at different DM masses. With the help of obtained deviation of $C-\Lambda$ curves from the fitted curve when no DM is present, and consequently, the relative shift of MR curves, we constrain the mass of WIMP $M_{DM} \sim 20$ GeV, presuming stiffer equation of state- NL3- to be sacred. The neutron star, described by NL3 EOS, admixed with DM of particle mass $\sim 20$ GeV satisfies the mass and radius range of secondary compact object of GW190814 event, and thus it could be a possible candidate.