Numerical relativity in D-dimensional spacetimes - Collisions of black holes and wave extraction

Helvi Witek, Miguel Zilhao, Vitor Cardoso, Leonardo Gualtieri, Carlos Herdeiro, Andrea Nerozzi, Ulrich Sperhake

Black objects in higher dimensional space-times are fascinating. From a theoretical viewpoint, these objects can have a large variety of configurations like, e.g. black holes, black strings, black rings, etc. and complex stability phase diagrams. They might also play a key role in high energy physics: for energies above the Planck scale, gravity is the dominant interaction which, together with the hoop-conjecture, implies that the trans-Planckian scattering of point particles should be well described by black hole scattering. Thus, higher-dimensional scenarios with an effective Planck scale of the order of TeV predict black hole production in the LHC. In this setting, accurate predictions of the production cross-section and energy loss in the formation of black holes is crucial for more accurate phenomenological modelling in the existing black hole event generators.
Here, we study the head-on collision of two black holes, including a detailed treatment of gravitational wave extraction by using the Kodama-Ishibashi formalism in generic D-dimensional space-times and present the results of numerical simulations of the head-on collision in five space-time dimensions.