From Overview of BBH Simulations Physics Colloquium -- Oct 29 1998. byScott Klasky
The extrinsic curvature is a spacelike object which determines the contraction and shear of the normals to the hypersurface.
We can rewrite the ADM equations as:
¶t gij = Lb gij - 2 a Kij
¶t Kij = Lb Kij - Di Dj a + a(Rij + K Kij -2Kli Klj
where Lb Kij = bk ¶kKij + Kkj ¶i bk + Kik ¶jbk
Causal Differencing:
Before we describe causal differencing, a key ingredient for the evolution of black holes, we must state the desired properties of a black hole evolution scheme.
