Effects of dark matter on the nuclear and neutron star matter

Abstract

We study the dark matter (DM) effects on the nuclear matter (NM) parameters characterizing the equation of states of super dense neutron-rich nucleonic matter. The observables of the NM, i.e. incompressibility, symmetry energy and its higher order derivatives in the presence DM for symmetric and asymmetric NM are analysed with the help of an extended relativistic mean field model. The calculations are also extended to β-stable matter to explore the properties of the neutron star (NS). We analyse the DM effects on symmetric NM, pure neutron matter, and NS using NL3, G3, and IOPB-I forces. The binding energy per particle and pressure is calculated with and without considering the DM interaction with the NM systems. The influences of DM are also analysed on the symmetry energy and its different coefficients. The incompressibility and the skewness parameters are affected considerably due to the presence of DM in the NM medium. We extend the calculations to the NS and find its mass, radius and the moment of inertia for static and rotating NS with and without DM contribution. The mass of the rotating NS is considerably changing due to rapid rotation with the frequency in the mass-shedding limit. The effects of DM are found to be important for some of the NM parameters, which are crucial for the properties of astrophysical objects.

Dark Matter Effects on the Compact Star Properties

“…In Refs. [38][39][40], we noticed that dark matter could affect the NS mass-radius relation and tidal deformability.…”

“…The accreted DM particles interact with baryons by exchanging standard model Higgs. The interacting Lagrangian is given in the form [38][39][40]44,56,65,66]:…”

“…The values of y and v are 0.07 and 246 GeV, respectively taken from the Refs. [38,56]. The m n , m χ and m h are the masses of the nucleon, DM, and Higgs equal to 939 MeV, 200 GeV and 125 GeV, respectively.…”

“…[55]. In our recent works [38,56], we considered the fermionic DM, which interacts with nucleons via the Higgs mechanism. The effects of DM on the structure of NS were analysed.…”

“…In the present calculations, we use the DM admixed EOS as in Ref. [38] and analyse the results of the higher-order tidal Love numbers (electric-type and magnetic-type) and surficial love numbers of the NSs. With the increased sensitivity of upcoming third-generation GW detectors and gravitational-wave detection of BNS mergers, that analysis is potentially important [57,58].…”