Gravitational-wave extraction from neutron-star oscillations

TL;DR

This paper compares various gravitational-wave extraction methods in 3D simulations of neutron-star oscillations, highlighting differences and nonlinear effects in gravitational radiation emission.

Contribution

It introduces a comprehensive comparison of gravitational-wave extraction techniques in nonlinear neutron-star simulations, including nonlinear effects onset.

Findings

Different extraction methods yield consistent results in linear regimes.

Nonlinear effects become significant at higher oscillation amplitudes.

The study provides benchmarks for future gravitational-wave modeling from neutron stars.

Abstract

We compare different gravitational-wave extraction methods used in three-dimensional nonlinear simulations against linear simulations of perturbations of spherical spacetimes with matter. We present results from fully general-relativistic simulations of a system composed by an oscillating and non-rotating star emitting gravitational radiation. Results about the onset of non-linear effects are also shown.