News from Horizons in Binary Black Hole Mergers

The work proposes and demonstrates a way to extract “news from horizons” during BBH mergers by tracking quasi-local horizon quantities in numerical simulations. In particular, it relates the shear of the (dynamical) horizons to features in the emitted gravitational radiation, establishing a horizon-side analogue of waveform “chirp” information. The results show that aspects of near-horizon dynamics can be tied quantitatively to observable waveforms at infinity.

Phys. Rev. Lett. 125, 121101 (2020)