Kerr-AdS Black Holes and Force-Free Magnetospheres

Abstract

We obtain analogs of the Blandford-Znajek split monopole solution for force-free magnetospheres around a slowly rotating Kerr-AdS black hole. For small black holes, we find an analytic solution to first order in the ratio of horizon radius to AdS scale, $r_H/l$, which exhibits a radial Poynting flux and for $r_H/l\to 0$ smoothly approaches the Blandford-Znajek configuration in an asymptotically flat Kerr background. However, for large Kerr-AdS black holes with $r_H/l>1$, namely those for which the bulk black hole holographically describes the thermodynamics of a strongly-interacting boundary field theory, the existence of a globally well-defined timelike Killing vector external to the horizon suggests the absence of energy extraction through the Blandford-Znajek process. In this regime, we find that at least for slow rotation the force-free solution still exists but exhibits a range of angular velocities for the field lines, corresponding to the freedom in the dual field theory to rotate a magnetic field through a neutral plasma. As a byproduct of this work, we also obtain an analytic solution for a rotating monopole magnetosphere in pure AdS, analogous to the Michel solution in flat space.

arXiv comment37 pages, 9 figures; v2: comments added and typos corrected

References in corpus (19)

• Gauge Theory Correlators from Non-Critical String Theory
• Thermodynamics of Kerr-Newman-AdS Black Holes and Conformal Field Theories
• Rotation and the AdS/CFT correspondence
• A Measurement of the Electromagnetic Luminosity of a Kerr Black Hole
• The First Law of Thermodynamics for Kerr-Anti-de Sitter Black Holes
• The General Kerr-de Sitter Metrics in All Dimensions
• The evolution of unstable black holes in anti-de Sitter space
• Charged and rotating AdS black holes and their CFT duals
• Kerr-AdS/CFT Correspondence in Diverse Dimensions
• Supersymmetry of Anti-de Sitter Black Holes
• Large rotating AdS black holes from fluid mechanics
• Extracting black-hole rotational energy: The generalized Penrose process
• Force-Free Magnetosphere of an Accretion Disk -- Black Hole System. II. Kerr Geometry
• Exact Solutions to Force-Free Electrodynamics in Black Hole Backgrounds
• On classical super-radiance in Kerr-Newman-anti-de Sitter black holes
• Dyonic AdS black holes from magnetohydrodynamics
• A Class of Exact Solution to the Blandford-Znajek Process
• The role of the ergosphere in the Blandford-Znajek process
• Entropy of a Kerr-de Sitter black hole due to arbitrary spin fields

Cited by in corpus (6)

• Black hole energy extraction via stationary scalar clouds
• Force-Free Foliations
• On the existence of the Blandford-Znajek monopole for a slowly rotating Kerr black hole
• Force-free magnetosphere on near-horizon geometry of near-extreme Kerr black holes
• Blandford-Znajek process in vacuo and its holographic dual
• Conformal symmetry in force-free electrodynamics