An Implementation of DF-GHG with Application to Spherical Black Hole Excision

Abstract

We present an implementation of the dual foliation generalized harmonic gauge (DF-GHG) formulation within the pseudospectral code bamps. The formalism promises to give greater freedom in the choice of coordinates that can be used in numerical relativity. As a specific application we focus here on the treatment of black holes in spherical symmetry. Existing approaches to black hole excision in numerical relativity are susceptible to failure if the boundary fails to remain outflow. We present a method, called DF-excision, to avoid this failure. Our approach relies on carefully choosing coordinates in which the coordinate lightspeeds are under strict control. These coordinates are then combined with the DF-GHG formulation. After performing a set of validation tests in a simple setting, we study the accretion of large pulses of scalar field matter on to a spherical black hole. We compare the results of DF-excision with a naive setup. DF-excision proves reliable even when the previous approach fails.

18 pages, 7 figures

References in corpus (7)

• Solving Einstein's Equations With Dual Coordinate Frames
• Stable radiation-controlling boundary conditions for the generalized harmonic Einstein equations
• Dynamical Excision Boundaries in Spectral Evolutions of Binary Black Hole Spacetimes
• A numerical study of the quasinormal mode excitation of Kerr black holes
• Evolutions of centered Brill waves with a pseudospectral method
• Revisiting Event Horizon Finders
• The Hyperboloidal Numerical Evolution of a Good-Bad-Ugly Wave Equation