The remains of a spinning, hyperbolic encounter

TL;DR

This paper presents a semi-analytic method to construct gravitational wave polarization states for unbound spinning compact binaries, incorporating spin-orbit interactions and amplitude corrections, with applications to hyperbolic encounters.

Contribution

It introduces a new approach to model GW polarization states including spin effects and amplitude corrections for hyperbolic orbits, improving upon previous models.

Findings

Validated the method against non-spinning binary results

Provided amplitude corrections at 1PN order for hyperbolic orbits

Compared GW signals with existing theoretical predictions

Abstract

We review a recently proposed approach to construct gravitational wave (GW) polarization states of unbound spinning compact binaries. Through this rather simple method, we are able to include corrections due to the dominant order spin-orbit interactions, in the quadrupolar approximation and in a semi-analytic way. We invoke the 1.5 post-Newtonian (PN) accurate quasi-Keplerian parametrization for the radial part of the dynamics and impose its temporal evolution in the PN accurate polarization states equations. Further, we compute 1PN accurate amplitude corrections for the polarization states of non-spinning compact binaries on hyperbolic orbits. As an interesting application, we perform comparisons with previously available results for both the GW signals in the case of non-spinning binaries and the theoretical prediction for the amplitude of the memory effect on the metric after the hyperbolic passage.