Year: 2025
Type: article
Abstract: We demonstrate that, in the presence of an external magnetic field, an uncharged classical Schwarzschild black hole moving superluminally in a dielectric with permittivity ε > 1 produces Cherenkov emission. This is a new physical effect: classical (nonquantum) emission of electromagnetic waves by a completely charge-neutral “particle.” The governing equations (involving general relativity, electromagnetism, and the physics of continuous media) have no external electromagnetic source—it is the distortion of the initial electromagnetic fields by the gravity of the black hole that plays the role of a superluminally moving source. The effect relies on nonzero values of both the magnetic field and the gravitational radius, as well as on the usual Cherenkov condition on the velocity, v / c > 1 / ε . Unlike Cherenkov emission by a point charge, the effective source in this case is spatially distributed, with emission generated along the single Cherenkov emission cone. The emitted spectrum is red dominated, with power ∝ d k z / | k z | for wave numbers | k z | ≤ 1 / R G , where R G is the Schwarzschild radius. We comment on possible observability of this process during black hole–neutron star mergers.
Authors: Sergei Khlebnikov, Maxim Lyutikov
Institution: Purdue University West Lafayette
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4410120784