We obtain the equation of state (EoS) for two-color QCD at low temperature and high density from the lattice Monte Carlo simulation. We find that the velocity of sound exceeds the relativistic limit (c_s^2/c^2=1/3) after BEC-BCS crossover in the superfluid phase. Such an excess of the sound velocity is predicted by several effective theories but is previously unknown from any lattice calculations for QCD-like theories.
This finding might have possible relevance to the EoS of neutron star matter revealed by recent measurements of neutron star masses and radii.
This talk is based on arXiv:2207.01253.