We present two recent parametrizations of the equation of state ( FSU2R and FSU2H models ) that reproduce the properties of nuclear matter and finite nuclei , fulfill constraints on high-density matter stemming from heavy-ion collisions , produce 2 M _ { \odot } neutron stars , and generate neutron star radii below 13 km .
Making use of these equations of state , cooling simulations for isolated neutron stars are performed .
We find that two of the models studied , FSU2R ( with nucleons ) and , in particular , FSU2H ( with nucleons and hyperons ) , show very good agreement with cooling observations , even without including nucleon pairing .
This indicates that cooling observations are compatible with an equation of state that produces a soft nuclear symmetry energy and , thus , generates small neutron star radii .
Nevertheless , both schemes produce cold isolated neutron stars with masses above 1.8 M _ { \odot } .