Charging up boosted black holes

• DOI: 10.1103/physrevd.107.044055
• Publication Date: 2023-02-22T15:15:40Z
• Authors: Prakruth Adari; Roman Berens; Janna Levin
• Keywords: High Energy Physics - Theory; High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th); 0103 physical sciences; FOS: Physical sciences; General Relativity and Quantum Cosmology (gr-qc); Astrophysics - High Energy Astrophysical Phenomena; 01 natural sciences; General Relativity and Quantum Cosmology

23 pages, 12 figures v2: added references v3: added subsection 3.1.1, replaced grainy figures in section 3.1, edited language<br/>Contrary to a prevailing assumption that black holes would swiftly discharge, we argue that black holes can charge preferentially when boosted through an ambient magnetic field. Though the details are very different, the preference for charge is related to the precipitation of the Wald charge on a spinning black hole in an ambient magnetic field. The gravito-electrodynamics upstage naive arguments about screening electric fields in determining the value of the charge accrued. Charged test particles, which build up the black hole charge, exhibit chaotic behavior as evidenced by fractal basin boundaries between dynamical regions. Charged, boosted black holes will generate their own electromagnetic fields and thereby their own luminous signatures, even if they are initially bare. We therefore add boosted black holes to the growing list of potentially observable black hole signatures, alongside black hole batteries and black hole pulsars. The implications should be relevant for supermassive black holes that are boosted relative to a galactic magnetic field as well as black holes merging with magnetized neutron stars.<br/>