Quick Overview of the Physics.
Evolve 2 black holes on a computer. Need to provide controllable convergent algorithms to compute gravitational waveforms which arise from black hole encounters, and which are relevant to astrophysical events and may be used to predict signals which can be used for detection by ground and space based detectors (LIGO).
We decompose the four-dimensional covariance of Einstein’s equations so that is is possible to pose them as a Cauchy evolution problem.
Fundamental variables are: gij , Kij , a, bi . Total # of 3D variables in our code=112. We make use of F90 data structures to easily handle the tensor notation.
To achieve long-term stability we cut out the singularity from the computational domain. (At the Apparent Horizon-which we must solve an elliptic equation to find this minimally trapped surface.