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arXiv · 2012.03952

Kerr black holes with synchronised axionic hair

Jorge F. M. Delgado·Carlos A. R. Herdeiro·Eugen Radu
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Abstract

We construct and analyse Kerr black holes (BHs) with synchronised axionic hair. These are the BH generalisations of the recently constructed rotating axion boson stars arXiv:2005.05982. Such BHs are stationary, axially symmetric, asymptotically flat solutions of the complex Einstein-Klein-Gordon theory with a QCD axion-like potential. They are regular everywhere on and outside the event horizon. The potential is characterised by two parameters: the mass of the axion-like particle, $m_a$ and the decay constant $f_a$. The limit $f_a \rightarrow \infty$ recovers the original example of Kerr BHs with synchronised scalar hair arXiv:1403.2757. The effects of the non-linearities in the potential become important for $f_a \lesssim 1$. We present an overview of the parameter space of the solutions together with a study of their basic geometric and phenomenological properties, for an illustrative value of the coupling that yields a non-negligible impact of the self-interactions.

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Jorge F. M. Delgado, Carlos A. R. Herdeiro, Eugen Radu. 2020-12-07. Kerr black holes with synchronised axionic hair. https://doi.org/10.1103/physrevd.103.104029

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