“From Neutronstars to Hybridstars” and “Quarkstars and Chiral Phase Transition”

We present the results of two master theses regarding the first dynamical simulations of a twinstar collapse in full general relativity.
The thesis “From Neutronstars to Hybridstars” (by S. Yilmaz) is based on a hybrid equation of state including a hadron-quark phase transition at high densities (~ 3-4 nuclear densities), while the thesis “Quarkstars and Chiral Phase Transition” (by C. Mitropoulos) uses an equation of state which is based on the chiral SU(3) quark-meson model featuring a chiral phase transition from a chirally non-restored phase to a restored one.
In both cases, the mass-radius relation of the resulting compact objects show a twin star behaviour. The dynamical evolution of a number of initial configurations and perturbations of the star have been performed using the Einstein-Toolkit (WhiskyTHC). Several time dependent properties of the twin star collapse have been investigated (e.g. maximal density of the simulated compact objects, velocity and density distributions) and an oscillatory behaviour between the twin star configurations has been found.