Gravitational effects of condensed dark matter on strange stars

In the present work we study the gravitational effects of condensed dark matter on strange stars. We consider self-interacting dark matter particles with properties consistent with current observational constraints, and dark matter inside the star is modeled as a Bose-Einstein condensate. We integrate numerically the Tolman-Oppenheimer-Volkoff equations in the two-fluid formalism assuming that strange stars are made of up to 4 percent dark matter. It is shown that for a mass of the dark matter particles in the range 50–160 MeV strange stars are characterized by a maximum mass and radius similar to the ones found for neutron stars.

Figure 1

Mass-radius diagram for $K=4/B$ and three different dark matter fractions: $\epsilon =0.02$ (red), $\epsilon =0.05$ (green) and $\epsilon =0.09$ (blue). The standard diagram without dark matter (black) is also shown for comparison.

Figure 2

Mass-radius diagram for $K=150/B$ and three different dark matter fractions: $\epsilon =0.02$ (gray), $\epsilon =0.035$ (magenta) and $\epsilon =0.05$ (pink). The standard diagram without dark matter (black) is also shown for comparison.

Figure 3

Mass difference compared to standard results (without dark matter) versus radius difference for $KB=4$ (red) and $KB=150$ (blue).