We’re back to predicting the excitation amplitude of black hole merger ringdowns. We already looked into the simpler case of binaries with aligned spins, and now tried to study the full problem of binaries with misaligned (i.e. processing) spins. Well, this is a hard problem! It’s not even clear which mode is the stronger one anymore, and finding suitable coordinates is not at all trivial. While this is just a first exploration, there’s so much interesting phenomenology here! Do it yourself with the postmerger package.

Francesco Nobili, Swetha Bhagwat, Costantino Pacilio, Davide Gerosa.
arXiv:2504.17021 [gr-qc].