Routaray, PinkuPinkuRoutarayQuddus, AbdulAbdulQuddusChakravarti, KabirKabirChakravartiKumar, BharatBharatKumar2025-08-312025-08-312023-11-0110.1093/mnras/stad26282-s2.0-85173275777https://d8.irins.org/handle/IITG2025/26590In this study, we investigate the impact of weakly interacting massive particles (WIMPs) dark matter (DM) on C-Λ universal relations, GW170817 posterior, and radial oscillations of neutron stars (NSs) by considering the interactions of uniformly trapped neutralinos as a DM candidate with the hadronic matter through the exchange of the Higgs boson within the framework of the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The hadronic equation of state (EOS) is modelled using the relativistic mean-field (RMF) formalism with IOPB-I, G3, and quark-meson coupling (QMC)-RMF series parameter sets. The presence of DM softens the EOS at both the background and the perturbation levels that implies a small shift to the left in the posterior accompanied by a much larger jump in the left of the mass-radius curves with increasing DM mass. It is observed that EOSs with DM also satisfy the C-Λ universality relations among themselves but get slightly shifted to the right in comparison to that without considering DM. Additionally, we find that the inclusion of DM allows the mass-radius (M-R) curves to remain consistent with observational constraints for HESS J1731-347, indicating the possibility of classifying it as a dark matter-admixed neutron star (DMANS). Moreover, we explore the impact of DM on the radial oscillations of pulsating stars and investigate the stability of NSs. The results demonstrate a positive correlation between the mass of DM and the frequencies of radial oscillation modes.falsedark matter | gravitational waves | neutron star mergers | stars: neutronArticle136529665492-54991 November 202314arJournal15