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arXiv · 2507.01919

Nonlinearities in Kerr Black Hole Ringdown from the Penrose Limit

D. Perrone·A. Kehagias·A. Riotto
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Abstract

We provide a fully analytical approach to calculate the nonlinearities of the gravitational waves in the ringdown of a Kerr black hole in the eikonal limit. The corresponding quasi-normal modes are associated to the orbits of a closed circular null geodesic and the problem can be analyzed by taking the Penrose limit around it. We calculate analytically the amplitude and the phase of the quadratic quasi-normal modes as well as its dependence on the black hole spin.

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D. Perrone, A. Kehagias, A. Riotto. 2025-07-02. Nonlinearities in Kerr Black Hole Ringdown from the Penrose Limit. https://arxiv.org/abs/2507.01919

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