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arXiv · 2008.01213

Thermodynamics of two aligned Kerr-Newman black holes

H. García-Compeán·V. S. Manko·C. J. Ramírez-Valdez
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Abstract

Using the notion of thermodynamic length, the first law of thermodynamics is consistently derived for two binary configurations of equal Kerr-Newman black holes separated by a massless strut. Like in the electrostatic systems of two Reissner-Nordstr\"om black holes and stationary vacuum systems of two Kerr black holes considered earlier, the thermodynamic length $\ell$ turns out to be defined by the same simple formula $\ell=L\exp(\gamma_0)$, $L$ being the coordinate length of the strut and $\gamma_0$ the value of the metric function $\gamma$ on the strut, which permits the elaboration of $\ell$ in a concise analytic form. The expression of the free energy in the case of two generic Kerr-Newman black holes is also proposed.

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H. García-Compeán, V. S. Manko, C. J. Ramírez-Valdez. 2020-08-03. Thermodynamics of two aligned Kerr-Newman black holes. https://doi.org/10.1103/physrevd.103.104001

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