Height-function-based 4D reference metrics for hyperboloidal evolution

Understand

Hyperboloidal slices are spacelike slices that reach future null infinity.

• Their asymptotic behaviour is different from Cauchy slices, which are traditionally used in numerical relativity simulations.
• This work uses free evolution of the formally-singular conformally compactified Einstein equations in spherical symmetry.
• One way to construct gauge conditions suitable for this approach relies on building the gauge source functions from a time-independent background spacetime metric.