Multiparameter multipolar test of general relativity with gravitational waves

Understand

Amplitude and phase of the gravitational waveform from compact binary systems can be decomposed in terms of their mass- and current-type multipole moments.

• In a modified theory of gravity, one or more of these multipole moments could deviate from general theory of relativity.
• In this work, we show that a waveform model that parametrizes the amplitude and phase in terms of the multipole moments of the binary can facilitate a novel multiparameter test of general relativity with exquisite precision.
• Using a network of next-generation gravitational-wave observatories, simultaneous deviation in the leading seven multipoles of a GW190814-like binary can be bounded to within 6%--40% depending on the multipole order, while supermassive black hole mergers observed by the Laser Interferometer Space Antenna achieve a bound of 0.3%--2%.