Post by amir on Jun 26, 2015 21:39:01 GMT
So according to some hydrodynamic studies done with Burn-UD there is more than one way that the phase transition becomes explosive (quark nova):
1) The Niebergal et al. 2010 paper gave subsonic burning speeds for 1D hadronic-quark matter combustion but they also discovered a deleptonization instability: the energy sapped from the front by the neutrinos being released in the combustion can slow down unevenly the burning interface, wrinkling it and creating an instability. This instability either lead to acceleration of the front and thus DDT or gravitational core collapse. A 2D simulation that resolves this wrinkling would help us understand more this instability.
2) Transition to Color flavored locked quark matter (CFL)? Some recent simulations we've done with Burn-UD by imposing a transition to CFL give quite interesting preliminary results. The simulation triggers two fronts, the conversion of ud to non-superconducting uds, and also another conversion front of uds to CFL. The uds-CFL front seems to be be supersonic and much faster than the ud-uds front. However these results aren't completely conclusive yet. Another hint that these simulations give is that CFL in the MIT Bag Model picture stiffens the equation of state which generates a large pressure gradient that could accelerate the burning front as well.
So right now, the most important approaches to be able to explore the explosive regimes of the hadronic-quark matter phase transition are:
1) Finish implementing 2D to burnud in order to be able to study the deleptonization instability.
2) Finish implementing CFL to see if CFL could be the ingredient that makes the burning speed supersonic.
1) The Niebergal et al. 2010 paper gave subsonic burning speeds for 1D hadronic-quark matter combustion but they also discovered a deleptonization instability: the energy sapped from the front by the neutrinos being released in the combustion can slow down unevenly the burning interface, wrinkling it and creating an instability. This instability either lead to acceleration of the front and thus DDT or gravitational core collapse. A 2D simulation that resolves this wrinkling would help us understand more this instability.
2) Transition to Color flavored locked quark matter (CFL)? Some recent simulations we've done with Burn-UD by imposing a transition to CFL give quite interesting preliminary results. The simulation triggers two fronts, the conversion of ud to non-superconducting uds, and also another conversion front of uds to CFL. The uds-CFL front seems to be be supersonic and much faster than the ud-uds front. However these results aren't completely conclusive yet. Another hint that these simulations give is that CFL in the MIT Bag Model picture stiffens the equation of state which generates a large pressure gradient that could accelerate the burning front as well.
So right now, the most important approaches to be able to explore the explosive regimes of the hadronic-quark matter phase transition are:
1) Finish implementing 2D to burnud in order to be able to study the deleptonization instability.
2) Finish implementing CFL to see if CFL could be the ingredient that makes the burning speed supersonic.