We explore the equation of state (EOS) for neutron star matter combined with dark matter and investigate the influence of dark matter on neutron star properties. We also analyze the impact of symmetry energy on dark matter admixed neutron stars, incorporating the effects of the ${\mathrm{\Lambda }}_v$ coupling. Using the relativistic mean field model with the S271 parameter and ${\mathrm{\Lambda }}_v$ values of 0.000 and 0.030, we investigate the interaction between fermionic dark matter and pure nucleonic matter through the Higgs portal mechanism. Our results indicate that the presence of dark matter softens the EOS and reduces the tidal deformability of neutron stars. The GW170817 event imposes restrictions on the tidal deformability of binary neutron stars, ruling out stiff equations of state. We observe that the Fermi momentum ($k_F^{\mathrm{DM}}$) of dark matter has a more significant impact on neutron star properties, such as maximum mass, radius, and tidal deformability, compared to the ${\mathrm{\Lambda }}_v$ coupling. Nevertheless, our results for S271 with ${\mathrm{\Lambda }}_v=0.000$ and 0.030, incorporating fermionic dark matter, are consistent with the tidal deformability limit derived from the GW170817 observation.

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• Nuclear astrophysics