Role of density profile of sub-GeV dark matter in the properties of dark matter admixed quark stars with Bayesian analysis of dark-NJL model

Abstract

We investigate the structural and oscillation properties of dark matter (DM) admixed strange quark stars (DMSQSs). The strange quark matter (SQM) is described with the well-known Nambu-Jona-Lasino (NJL) model and the self-interacting fermionic DM is included in a systematic manner. The self-interaction of DM is of four-Fermi type and the overall DM density is considered as a function of the baryon density of SQM with two free parameters ($\alpha$, $\rho_{sc}$). This work is the first to consider four-Fermi interactions between fermionic DM and SQM in DMSQSs. Certain experiments like LZ, XENON, DarkSide, CRESST, and LHC have almost ruled out the possibility of contact interaction between SQM and massive DM (in GeV order). Recently, the quest for sub-GeV DM has garnered significant attention. We show that recent astrophysical constraints on the structural properties of compact stars also do not support the presence of massive DM in DMSQSs. On the other hand, we find sub-GeV DM to successfully concur with such observational constraints. We also calculate the fundamental $f$-mode frequency ($f_f$) of the DMSQSs, which shows universality with compactness, mean density, and tidal deformability. Further, we investigate the prospect of detection of $f_f$ with respect to the projected sensitivity of upcoming gravitational wave detectors like aLIGO, A+, Cosmic Explorer, and Einstein Telescope. In our DMSQS model, the three free parameters are $\alpha$, $\rho_{sc}$, and the ratio of repulsive to attractive interaction in SQM ($G_V/G_S$), which are optimized by Bayesian analysis in light of various recent astrophysical data.