3 research outputs found
Initial data for two Kerr-like black holes
We prove the existence of a family of initial data for the Einstein vacuum
equation which can be interpreted as the data for two Kerr-like black holes in
arbitrary location and with spin in arbitrary direction. When the mass
parameter of one of them is zero, this family reduces exactly to the Kerr
initial data. The existence proof is based on a general property of the Kerr
metric which can be used in other constructions as well. Further
generalizations are also discussed.Comment: revtex, 5 pages, no figure
Grazing Collisions of Black Holes via the Excision of Singularities
We present the first simulations of non-headon (grazing) collisions of binary
black holes in which the black hole singularities have been excised from the
computational domain. Initially two equal mass black holes are separated a
distance and with impact parameter . Initial data are
based on superposed, boosted (velocity ) solutions of single black
holes in Kerr-Schild coordinates. Both rotating and non-rotating black holes
are considered. The excised regions containing the singularities are specified
by following the dynamics of apparent horizons. Evolutions of up to are obtained in which two initially separate apparent horizons are present
for . At that time a single enveloping apparent horizon forms,
indicating that the holes have merged. Apparent horizon area estimates suggest
gravitational radiation of about 2.6% of the total mass. The evolutions end
after a moderate amount of time because of instabilities.Comment: 2 References corrected, reference to figure update
Numerical Relativity: A review
Computer simulations are enabling researchers to investigate systems which
are extremely difficult to handle analytically. In the particular case of
General Relativity, numerical models have proved extremely valuable for
investigations of strong field scenarios and been crucial to reveal unexpected
phenomena. Considerable efforts are being spent to simulate astrophysically
relevant simulations, understand different aspects of the theory and even
provide insights in the search for a quantum theory of gravity. In the present
article I review the present status of the field of Numerical Relativity,
describe the techniques most commonly used and discuss open problems and (some)
future prospects.Comment: 2 References added; 1 corrected. 67 pages. To appear in Classical and
Quantum Gravity. (uses iopart.cls