Seminario
"3D collapse to Kerr black holes: dynamics of matter, trapped surfaces and gravitational radiation and Beyond."
Relatore: Luca Baiotti SISSA, Trieste Note: Cambio di Orario
Sala Feynman
12 Ottobre 2004 ore
Abstract

We present a new threedimensional fully general relativistic
hydrodynamics code using highresolution shockcapturing techniques
and a conformal traceless formulation of the Einstein equations. We
discuss its application to the study of the gravitational collapse of
uniformly rotating neutron stars to Kerr black holes. The initial
stellar models are modelled as relativistic polytropes which are
either secularly or dynamically unstable and with angular velocities
which range from slow rotation to the massshedding limit. We
investigate the gravitational collapse by carefully studying not only
the dynamics of the matter, but also that of the trapped surfaces,
{it i.e.} of both the apparent and event horizons formed during the
collapse. The ability to successfully perform these simulations for
sufficiently long times relies on excising a region of the
computational domain which includes the singularity and is within the
apparent horizon. We also present the first calculation of
gravitationalwave emission produced in the gravitational collapse of
uniformly rotating neutron to Kerr black holes in fully
threedimensional simulations. An essential aspect of these
simulations is the use of progressive meshrefinement techniques which
allow to move the outer boundaries of the computational domain to
regions where gravitational radiation attains its asymptotic form. The
waveforms have been extracted using a gaugeinvariant approach in
which the numerical spacetime is matched with the nonspherical
perturbations of a Schwarzschild spacetime. Most of our simulations are
performed on the Albert100 cluster in Parma.


