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arXiv · 1805.10512

General relativistic formulas for mass and spin of a Kerr black hole in terms of redshifts and orbital parameters

Alfredo Herrera-Aguilar·Raúl Lizardo-Castro·Ulises Nucamendi
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Abstract

We derive closed formulas for the mass and spin parameters of a Kerr black hole in terms of a minimal quantity of observational data: the red-/blue-shifts of photons emitted by massive particles (stars) moving on geodesics around the black hole and their respective orbital radius. It turns out that given a set of two (three) stars revolving around the black hole, these formulas involve just eight (twelve) observational data. For the case of a single star orbiting the black hole we need a minimal set of four observational measurements to analytically determine both parameters.

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Alfredo Herrera-Aguilar, Raúl Lizardo-Castro, Ulises Nucamendi. 2021-02-16. General relativistic formulas for mass and spin of a Kerr black hole in terms of redshifts and orbital parameters. https://doi.org/10.1002/asna.202113904

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