Causality and perturbative-QCD constraints on first-order phase transitions in neutron stars
The study compares causality bounds for neutron stars with and without a first-order phase transition (FOPT) in their equation of state (EOS). Results show that FOPT EOSs deviate significantly from smooth ones, creating distinct regions in the mass-radius diagram. This deviation allows researchers to rule out specific FOPT models when matching observations like pulsar data.