Simulation of a Boosted Black Hole with Overlapping Coordinate Systems

We discuss the simulation of a boosted Kerr-Schild black hole using overlapping spheriodal grids around the excision region. We make use of constrained evolution, periodically solving the constraints to better than truncation error. Fisheye is used to increase the size of the domain while Robin boundary conditions are used at the outer boundary. We discuss the current state of the code and the impediments to long-time integration.