On the non-minimal coupling of magnetic fields with gravity in Schwarzschild spacetime. (15th March 2023)

• Record Type: Journal Article
• Authors: Ravi, Kumar; Pavlović, Petar; Saveliev, Andrey
• Is Part Of: Classical and quantum gravity. Volume 40:Number 7(2023)
• Publication Date: 2023-03-15
• Subjects: non-minimal coupling -- Schwarzschild spacetime -- magnetic fields -- innermost stable circular orbit -- black hole -- effective potential; Quantum gravity -- Periodicals; Gravitation -- Periodicals; Relativity (Physics) -- Periodicals; Space and time -- Periodicals; Periodicals; 521.1
• DOI: 10.1088/1361-6382/acc0ca
• Languages: English
• ISSNs: 0264-9381

Abstract

Abstract: In this work we study the effects of non-minimal coupling between electromagnetism and gravity, which are motivated by quantum effects such as vacuum polarization. We investigate the modification of both asymptotically dipole and uniform magnetic fields around a Schwarzschild black hole that come as the result of non-minimal coupling. While in both cases the magnetic field gets enhanced or suppressed with respect to the case of minimal coupling, depending on the sign of non-minimal coupling parameter, in the case of a background uniform magnetic field the direction of the magnetic field also alters in the vicinity of the black hole horizon. We have discussed the possible astrophysical and cosmological sources for which the vacuum polarization may be at play, while also discussing the observational effects, in particular the possibility of synchrotron radiation from the vicinity of a black hole. We conclude that such observations could be used to constrain the value of the non-minimal coupling parameter.