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Ringing out General Relativity: Quasi-normal mode frequencies for black holes of any spin in modified gravity (2405.12280v3)
Published 20 May 2024 in gr-qc, astro-ph.HE, and astro-ph.IM
Abstract: After black holes collide, the remnant settles to a stationary state by emitting gravitational waves. Once non-linearities subside, these ringdown waves are dominated by exponentially-damped sinusoids, or quasinormal modes. We develop a general method using perturbative spectral expansions to calculate the quasinormal-mode frequencies and damping times in a wide class of modified gravity theories for black holes with any subextremal spin. We apply this method to scalar-Gauss-Bonnet gravity to show its accuracy, thus enabling robust ringdown tests with gravitational wave data.