Gravitational Radiation from the radial infall of highly relativistic point particles into Kerr black holes

TL;DR

This paper analyzes gravitational waves from high-energy collisions of relativistic particles with Kerr black holes, revealing universal spectral features and estimating significant energy emission during such events, with implications for black hole production at colliders.

Contribution

It introduces a formalism to compute gravitational radiation from relativistic particle-Kerr black hole collisions and identifies universal spectral features independent of black hole spin.

Findings

High-energy collisions produce characteristic gravitational wave spectra.

Approximately 35% of the collision energy can be emitted as gravitational waves.

Speed-of-light black hole collisions are highly efficient gravitational wave sources.

Abstract

In this paper, we consider the gravitational radiation generated by the collision of highly relativistic particles with rotating Kerr black holes. We use the Sasaki-Nakamura formalism to compute the waveform, energy spectra and total energy radiated during this process. We show that the gravitational spectrum for high-energy collisions has definite characteristic universal features, which are independent of the spin of the colliding objects. We also discuss possible connections between these results and the black hole-black hole collision at the speed of light process. With these results at hand, we predict that during the high speed collision of a non-rotating hole with a rotating one, about 35% of the total energy can get converted into gravitational waves. Thus, if one is able to produce black holes at the Large Hadron Collider, as much as 35% of the partons' energy should be emitted during the so called balding phase. This energy will be missing, since we don't have gravitational wave detectors able to measure such amplitudes. The collision at the speed of light between one rotating black hole and a non-rotating one or two rotating black holes turns out to be the most efficient gravitational wave generator in the Universe.