Observing gravitational wave polarizations with LISA-TAIJI network

Understand

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.