Speaker
Description
Studies of explosive astrophysical systems as core-collapse supernovae and binary neutron star mergers require equations of state (EOS) covering wide domains of baryon number density 10^{-14} fm^{-3} ≤ n_B ≤ 1.5 fm^{-3} , temperature 0 ≤ T ≤ 100 MeV and electron fraction 0 ≤ Y_e=n_e /n_B ≤ 0.6. Advances in this field during the last decade make that about 100 such EOS are presently available on the CompOSE database (https://compose.obspm.fr/), out of which 35 account for exotic degrees of freedom.
In the present talk we shall investigate the thermal properties (thermal energy density and pressure; thermal and adiabatic index; specific heat at constant volume and at constant pressure; entropy per baryon; speed of sound) of some of these models. Comparison between predictions of these models allows to identify the model-dependence of the finite temperature behavior; consequences of nucleation of exotic species; artifacts connected to the way in which the hadron to quark phase transition was dealt with; the role of Landau/Dirac effective masses.
The so-called Gamma-law, commonly used to supplement cold EOS with a thermal component, is found not to provide a reliable solution of the thermal behavior.
Finally, we shall discuss properties of hot stars, where profiles of entropy per baryon and electron fraction are inspired from proto-neutron star evolution.