Evolution of Brill waves with an adaptive pseudospectral method

As a first application of the new adaptive mesh functionality pseudospectral numerical relativity code bamps, we evolve twist-free, axisymmetric gravitational waves close to threshold collapse. We consider six different one-parameter families Brill wave initial data; two centered and four off-centered families. Of these latter have not been treated before. Within each family, tune parameter towards black hole formation. The results for data agree with earlier work. Our key are first, that collapse global peak in curvature appears on symmetry axis but away from origin, indicating limit they will around disjoint centers. This is confirmed three by explicitly finding apparent horizons large peaks. Second, find evidence neither strict discrete-self-similarity nor universal power-law scaling quantities. Finally, as Ledvinka Khirnov's recent study, approximately strong features. These features appear multiple times within individual spacetimes furthermore present all