Gravitational Waves from a Core g Mode in Supernovae as Probes of the High-Density Equation of State

Using relativistic supernova simulations of massive progenitor stars with a quark-hadron equation of state (EOS) and a purely hadronic EOS, we identify a distinctive feature in the gravitational-wave signal that originates from a buoyancy-driven mode (g mode) below the proto-neutron star convection zone. The mode frequency lies in the range 200 less than or similar to f less than or similar to 800 Hz and decreases with time. As the mode lives in the core of the proto-neutron star, its frequency and power are highly sensitive to the EOS, in particular the sound speed around twice saturation density.