Testing general relativity using higher-order modes of gravitational waves from binary black holes

Understand

Recently, strong evidence was found for the presence of higher-order modes in the gravitational wave signals GW190412 and GW190814, which originated from compact binary coalescences with significantly asymmetric component masses.

• This has opened up the possibility of new tests of general relativity by looking at the way in which the higher-order modes are related to the basic signal.
• Here we further develop a test which assesses whether the amplitudes of sub-dominant harmonics are consistent with what is predicted by general relativity.
• To this end we incorporate a state-of-the-art waveform model with higher-order modes and precessing spins into a Bayesian parameter estimation and model selection framework.