TOV Perturbations

This is an old textual note which I digitize here because I throw the textual one away. Has to be sorted in accordingly

Plan from an old coding week:

• Trento: Artificial viscosity
• Frankfurt: Perturbed TOV, with THC, FIL

Perturbations:

1. p = alpha * p_0
2. rho = rho_0 * (1 + alpha * cos(2pi r/R))

Trento codes:

• Tractor: AMR-3D (=all features, but slow)
• Ferrari: ADER-DG (=prototype, clean, vectorized, fast, but only unigrid and no limiter)