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arXiv · 2405.05315

Impact of a plasma on the relaxation of black holes

Enrico Cannizzaro·Thomas F. M. Spieksma·Vitor Cardoso·Taishi Ikeda
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Abstract

Our universe is permeated with interstellar plasma, which prevents propagation of low-frequency electromagnetic waves. Here, we show that two dramatic consequences arise out of such suppression; (i) if plasma permeates the light ring of a black hole, electromagnetic modes are screened entirely from the gravitational-wave signal, changing the black hole spectroscopy paradigm; (ii) if a near vacuum cavity is formed close to a charged black hole, as expected for near equal-mass mergers, ringdown "echoes" are excited. The amplitude of such echoes decays slowly and could thus serve as a silver bullet for plasmas near charged black holes.

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Enrico Cannizzaro, Thomas F. M. Spieksma, Vitor Cardoso, Taishi Ikeda. 2024-05-08. Impact of a plasma on the relaxation of black holes. https://arxiv.org/abs/2405.05315

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