Gravity Seminar: Free hyperboloidal evolutions: current numerical efforts, Alex Vañó Viñuales, Instituto Superior Técnico (CENTRA), Lisbon, Portugal

Gravitational wave radiation is only unambiguously defined at future null infinity – the location in spacetime where light rays arrive and where global properties of spacetimes can be measured. A convenient way to include it in numerical relativity simulations is using hyperboloidal slices, which are spacelike and smooth, but reach future null infinity. I will review the current state of the art of two suitable free-evolution approaches. The first one uses conformal compactification, while the second one employs the dual-frame method. I will present some of their first tests in spherically symmetric simulations, showing the potential of the hyperboloidal approach. I will also give an update on current ongoing work towards 3D evolutions, as the final goal of this work is to provide a far-field numerical framework that includes null infinity for simulations of compact object mergers with accurate gravitational wave extraction.