FeaturesΒΆ

The library contains different types of 3-parametric EOS that can be accessed through a generic interface. It is quite simple to add custom EOS without modifying the library.

The interface provides the following functions:

  • \(P(\rho,\epsilon,Y_e)\)

  • \(c_s(\rho,\epsilon,Y_e)\)

  • \(\frac{\partial P}{\partial \rho}(\rho,\epsilon,Y_e)\)

  • \(\frac{\partial P}{\partial \epsilon}(\rho,\epsilon,Y_e)\)

  • \(s(\rho,\epsilon,Y_e)\) (optional)

  • \(T(\rho,\epsilon,Y_e)\) (optional)

Optionally, the above is also available in terms of temperature \(T\) instead of \(\epsilon\).

Further, each EOS comes with a validity region of the form

\[\begin{split}\rho_\mathrm{min} &\le \rho \le \rho_\mathrm{max} \\ Y_{e,\mathrm{min}} &\le Y_e \le Y_{e,\mathrm{max}} \\ \epsilon_\mathrm{min}(\rho, Y_e) &\le \epsilon \le \epsilon_\mathrm{max}(\rho, Y_e) \\ T_\mathrm{min}(\rho, Y_e) &\le T \le T_\mathrm{max}(\rho, Y_e) \\\end{split}\]

In addition, the global minimum \(h_0\) of the enthalpy over the valid region is given for each EOS.

The framework guarantees some physical constraints:

\[\begin{split}0 &\le c_s < 1 \\ 0 &\le P \le \rho_E \\ \rho_E &\ge 0 \\ h_0 &> 0\end{split}\]

Note

Only \(P(\rho,\epsilon,Y_e), h_0\), and the validity region are used for the primitive recovery, the other functions are intended for use in numerical relativity evolution codes.