Existing examples

Binary Black Hole example

The initial conditions consist in a superposition of two boosted black holes. The example uses an approximation for low boosts to solve the Hamiltonian constraint which is accurate up to order P^4.

The example can optionally be run using initial data from our standalone version of the TwoPunctures code. The TwoPunctures code is kept in a separate repository for licensing reasons. Instructions are provided in the README explaining how to build the BinaryBH example with TwoPunctures.

See Running the BinaryBH example for more details on this Example.

Kerr BH example

This is a stationary Kerr solution for high spin black holes, based on the semi isotropic Kerr-Schild coordinates proposed by Brandt and Seidel and revised by Liu, Etienne and Shapiro.

The evolution seen initially is simply the gauge evolution as the analytic initial data settles into the puncture gauge of the evolution - try visualising the conformal factor chi to see this.

The example is very minimal and is a good starting point for single black hole vacuum spacetimes.

Scalar Field examples

The ScalarFieldBH example takes the KerrBH example and adds in a scalar field as matter content in the evolution. The initial conditions are a single Kerr black hole immersed in a scalar field background which has a constant density value (allowing an easy solution of the constraints). The goal is to show how matter can be included in the evolution of a black hole.

A second example is the ScalarFieldCosmo example, that provides a starting point for a cosmological simulation.