Gravitational ringing of rotating black holes in higher-derivative gravity

Understand

We study gravitational perturbations of slowly-rotating black holes in a general effective-field-theory extension of general relativity that includes up to eight-derivative terms.

• We show that two Schr\"odinger-like equations with spin-dependent effective potentials govern the odd - and even-parity master variables.
• These equations are coupled for parity-violating corrections, and this coupling affects the quasinormal modes even at linear order in the higher-derivative corrections, due to their isospectrality in general relativity.
• We provide results for the shifts in the fundamental quasinormal mode frequencies at linear order in the spin, which we expect to be valuable for high-precision phenomenology through future gravitational wave observations.