Mirror Neutron Stars

The fundamental nature of dark matter is entirely unknown. A compelling candidate is Twin Higgs mirror matter, invisible hidden-sector cousins of the Standard Model particles and forces. This generically predicts mirror neutron stars, degenerate objects made entirely of mirror nuclear matter. We find their structure using realistic equations of state, robustly modified based on first-principle quantum chromodynamic calculations. We predict their detectability with gravitational waves and binary pulsars, suggesting an impressive discovery potential and ability to probe the dark sector.