Observing gravitational wave polarizations with LISA-TAIJI network

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.

Forecast for cosmological parameter estimation with gravitational-wave standard sirens from the LISA-Taiji network

“…LISA's orbit is proposed to be at the ecliptic plane behind the Earth with 20 • trailing angle, and Taiji is planed to be localized in front of the Earth with 20 • leading angle, so that LISA and Taiji could form a space-based network aimed at detecting GW signals within mHz range (i.e. 10 −4 Hz to 1 Hz) [92][93][94][95][96][97][98].…”

“…Orlando et al [97] proposed that the chirality of an isotropic SGWB can be detected by cross-correlating the data streams of the LISA and Taiji. Wang and Han [98] showed that the LISA-Taiji network could improve the observations on the anomalous polarization predicted by the theories beyond general relativity.…”