Charged black holes in de Sitter space: superradiant amplification of charged scalar waves and resonant hyperradiation

Understand

Black holes typically inhabit highly dynamical galactic environments and are frequently permeated by accretion media.

• The inevitable scattering of scalar, electromagnetic and gravitational waves off rotating and charged black holes provides a remarkable demonstration of the energy extraction and subsequent amplification of scattered waves under the expense of the compact object's rotational and electromagnetic energy; a phenomenon known as superradiance.
• Certain circumstances tremendously favor the energy extraction process in such extent that linear superradiant instabilities are triggered.
• We examine the superradiant amplification of monochromatic charged scalar fields impinging Reissner-Nordstr\"om-de Sitter black holes which are known to exhibit superradiantly unstable quasinormal modes.