The gravitomagnetic dynamo effect in accretion disks of rotating black holes

Abstract

view Abstract Citations (23) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Gravitomagnetic Dynamo Effect in Accretion Disks of Rotating Black Holes Khanna, Ramon ; Camenzind, Max Abstract We present a previously unknown dynamo effect that arises from the coupling of the gravitomagnetic field of a Kerr black hole with electromagnetic fields. The axisymmetric dynamo equations are derived in the 3 + 1 split of Kerr spacetime. They are formally identical to their equivalents in flat space, augmented by a general relativistic source term for the poloidal magnetic field provided by the gravitomagnetic field. There is no need for any particular small-scale plasma motions. The effect does, however, require finite conductivity and is enhanced by anomalous or turbulent magnetic diffusivity. The results of our time-dependent numerical simulations of the mean field dyanmo in a turbulent accretion disk prove that the gravitomagnetic dynamo has growing modes in the vicinity of a rotating black hole. Publication: The Astrophysical Journal Pub Date: November 1994 DOI: 10.1086/187611 Bibcode: 1994ApJ...435L.129K Keywords: Accretion Disks; Black Holes (Astronomy); Dynamo Theory; Gravitational Effects; Magnetohydrodynamics; Stellar Magnetic Fields; Stellar Rotation; Computerized Simulation; Magnetic Effects; Numerical Analysis; Plasma Oscillations; Poloidal Flux; Relativity; Astrophysics; ACCRETION; ACCRETION DISKS; BLACK HOLE PHYSICS; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS: MHD; RELATIVITY full text sources ADS |