Observing gravitational wave polarizations with LISA-TAIJI network

TL;DR

This paper explores how the combined LISA-TAIJI space missions can significantly enhance the detection of non-standard gravitational wave polarizations, testing theories beyond general relativity with improved sensitivity.

Contribution

It introduces a parameterized waveform model to analyze the joint LISA-TAIJI data for detecting additional gravitational wave polarizations beyond general relativity.

Findings

Joint LISA-TAIJI observations improve polarization measurement sensitivity by over 10 times.

The study quantifies the potential to detect alternative polarizations using parameterized post-Einsteinian parameters.

Results demonstrate the effectiveness of the combined network in testing gravity theories beyond Einstein's predictions.

Abstract

Two polarization modes of gravitational wave are derived from the general relativity which are plus and cross modes. However, the alternative theories of gravity can yield the gravitational wave with up to six polarizations. Searching for the polarizations beyond plus and cross is an important test of general relativity. In principle, one space-borne detector, like LISA, could measure the gravitational wave polarizations from a long time observation with its orbital motion. With the comparable sensitivities, the joint LISA and TAIJI missions will improve the observations on the polarization predictions of theories beyond general relativity. In this work, a class of parameterized post-Einsteinian waveform is employed to describe the alternative polarizations, and six parameterized post-Einsteinian parameters quantifying from general relativity waveform are examined by using the LISA-TAIJI network. Our results show that the measurements on amplitudes of alternative polarizations from joint LISA-TAIJI observation could be improved by more than 10 times compared to LISA single mission in an optimal scenario.