Possible maximum mass of dark matter existing in compact stars based on the self-interacting fermionic model
Abstract
The dark matter admixed neutron stars (DANSs) are studied using the two-fluid TOV equations separately, in which the normal matter (NM) and dark matter (DM) are simulated by the relativistic mean field theory and self-interacting fermionic model, respectively. A universal relationship MDmax = (0.269mf mI + 0.627)(1GeV mf )2M ⊙ is suggested, where MDmax is the maximum mass of DM existing in DANSs, mf is the particle mass of DM ranging from 5GeV to 1TeV, mI is the interaction mass scale with the value 300GeV (0.1GeV) for weak (strong) interaction DM model. This simple formula connects directly the microcosmic nature of DM particle with its macrocosmic mass existing in DANSs. Meanwhile, such a formula exhibits that the existence of NM has little effect on MDmax. It is found that the ratio of radius of DM in DANSs over MDmax is a constant with the value about 12 kmM ⊙ (7 kmM ⊙) for weak (strong) interaction DM cases. According to the calculated results, only for the strong interaction DM cases with mf = 5 to 10GeV and central energy density 𝜀D > 103MeV/fm3, DM has obvious effect on the mass of compact star. Compared with the energy density of DM in the Milky Way galaxy, ∼10-36MeV/fm3, the existence of DM might hardly affect the mass of compact stars in the Milky Way galaxy.
- Publication:
-
International Journal of Modern Physics D
- Pub Date:
- 2019
- DOI:
- 10.1142/S0218271819501487
- arXiv:
- arXiv:1805.01314
- Bibcode:
- 2019IJMPD..2850148W
- Keywords:
-
- Neutron stars;
- dark matter;
- relativistic mean field theory;
- weakly interacting massive particles;
- 97.60.Jd;
- 26.60.‑c;
- 21.60.Jz;
- 95.35.+d;
- Neutron stars;
- Hartree-Fock and random-phase approximations;
- Dark matter;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- Nuclear Theory
- E-Print:
- 13 pages, 7 figures