Possible Implications of Asymmetric Fermionic Dark Matter for Neutron Stars

Understand

We consider the implications of fermionic asymmetric dark matter for a "mixed neutron star" composed of ordinary baryons and dark fermions.

• We find examples, where for a certain range of dark fermion mass -- when it is less than that of ordinary baryons -- such systems can reach higher masses than the maximal values allowed for ordinary ("pure") neutron stars.
• This is shown both within a simplified, heuristic Newtonian analytic framework with non-interacting particles and via a general relativistic numerical calculation, under certain assumptions for the dark matter equation of state.
• Our work applies to various dark fermion models such as mirror matter models and to other models where the dark fermions have self interactions.