AMReX-Astro
sync self-consistent NSE update with tabular NSE
In nse_update_sdc.H, the tabular NSE has been written up in the SDC+NSE paper and was shown to be 2nd order. We should sync the self-consistent NSE up with it.
In nse_derivs we need the derivatives to calculate energies. And if we were to do the same, we will need Ydots if we calculate energy using e_nuc = -N_A * c^2 * dY_k/dt * m_k. So do I just call the rhs for it?
Also what if we carry the mass / molar fraction of the previous timestep and do a central difference do get the derivative?
we only want the energy from the weak reaction rates, not everything. So I think that we should add a function to pynucastro nets that evaluates just the energy from weak rates. We will need to call the tables each time, but it should not be too bad.
just to reiterate, so we want to do e_nuc = -N_A * c^2 * dY_k/dt * m_k. But using only weak rate contributions in dY_k/dt because in NSE, strong reactions should balance out and only weak reactions contribute. Then we do the same RK2 procedure in Tabular NSE.