Black-hole horizons as probes of black-hole dynamics I: post-merger recoil in head-on collisions

Understand

The understanding of strong-field dynamics near black-hole horizons is a long-standing and challenging prob- lem in general relativity.

• Recent advances in numerical relativity and in the geometric characterization of black- hole horizons open new avenues into the problem.
• In this first paper in a series of two, we focus on the analysis of the recoil occurring in the merger of binary black holes, extending the analysis initiated in [1] with Robinson- Trautman spacetimes.
• More specifically, we probe spacetime dynamics through the correlation of quantities defined at the black-hole horizon and at null infinity.