An equation of state for warm neutron degenerate matter

The equation of state of Langer et al. is extended to non-zero temperatures. The gas is considered to be an equilibrium mixture of degenerate neutrons, protons, electrons, positrons, negative muons and a single species of nucleus. The pressure and equilibrium particle concentrations are tabulated for densities and temperatures which may occur at the centre of a presupernova during gravitational collapse $$(2 \times {10}^{11} \lt \rho \lt {10}^{16} \text{g} \,\text{cm}^{-3}; {10}^{10} \lt T \lt 4.5 \times {10}^{11} \,\text{K}.$$ The results agree (to within a factor of 2) with the equation of state derived by El Eid & Hilf except at high densities or high temperatures.