0000000000390810

AUTHOR

Wolfgang Kastaun

0000-0003-3924-5745

showing 2 related works from this author

Implementation of a simplified approach to radiative transfer in general relativity

2013

We describe in detail the implementation of a simplified approach to radiative transfer in general relativity by means of the well-known neutrino leakage scheme (NLS). In particular, we carry out an extensive investigation of the properties and limitations of the NLS for isolated relativistic stars to a level of detail that has not been discussed before in a general-relativistic context. Although the numerous tests considered here are rather idealized, they provide a well-controlled environment in which to understand the relationship between the matter dynamics and the neutrino emission, which is important in order to model the neutrino signals from more complicated scenarios, such as binar…

High Energy Astrophysical Phenomena (astro-ph.HE)PhysicsNuclear and High Energy PhysicsGeneral relativityAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesPerturbation (astronomy)General Relativity and Quantum Cosmology (gr-qc)MechanicsGeneral Relativity and Quantum CosmologyNeutron starNumerical relativityStarsClassical mechanicsGravitational collapseRadiative transferNeutrinoAstrophysics - High Energy Astrophysical PhenomenaPhysical Review D
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On the black hole from merging binary neutron stars: how fast can it spin?

2013

The merger of two neutron stars will in general lead to the formation of a torus surrounding a black hole whose rotational energy can be tapped to potentially power a short gamma-ray burst. We have studied the merger of equal-mass binaries with spins aligned with the orbital angular momentum to determine the maximum spin the black hole can reach. Our initial data consists of irrotational binaries to which we add various amounts of rotation to increase the total angular momentum. Although the initial data violates the constraint equations, the use of the constraint-damping CCZ4 formulation yields evolutions with violations smaller than those with irrotational initial data and standard formul…

PhysicsNuclear and High Energy PhysicsAngular momentumAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesGeneral Relativity and Quantum Cosmology (gr-qc)General Relativity and Quantum CosmologyBlack holeGeneral Relativity and Quantum CosmologyRotating black holeBinary black holeTotal angular momentum quantum numberQuantum mechanicsExtremal black holeStellar black holeSpin-flip
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