Protoneutron stars and constraints on maximum and minimum mass of   neutron stars
  Constraints on minimum and maximum mass of ordinary neutron stars are imposed by the consideration of their early evolution (protoneutron star stage). Calculations are performed for a realistic standard model of hot, dense matter (Lattimer & Swesty 1991) valid for both supranuclear and subnuclear densities. Various assumptions concerning protoneutron star interior (large trapped lepton number, no trapped lepton number, isentropic, isothermal) are taken into account. 
D. Gondek, P. Haensel, J. L. Zdunik