Collision of spinning black holes in the close limit: The parallel spin case

TL;DR

This paper analyzes the gravitational radiation from the collision of slowly spinning black holes with parallel spins using perturbation theory, providing results consistent with previous Zerilli formalism studies.

Contribution

It applies Teukolsky formalism to model black hole collisions with parallel spins, extending previous work with a different perturbation approach.

Findings

Waveforms match previous Zerilli formalism results

Quantitative estimates of radiated energy and angular momentum

Validation of perturbation methods for close black hole collisions

Abstract

In this paper we consider the collision of black holes with parallel spins using first order perturbation theory of rotating black holes (Teukolsky formalism). The black holes are assumed to be close to each other, initially non boosted and spinning slowly. We estimate the properties of the gravitational radiation released from such an collision. The same problem was studied recently by Gleiser {\em et al.} in the context of the Zerilli perturbation formalism and our results for waveforms, energy and angular momentum radiated agree very well with the results presented in that work.