A general relativistic toroid around a black hole

Abstract

view Abstract Citations (48) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A General Relativistic Toroid around a Black Hole Nishida, Shogo ; Eriguchi, Yoshiharu Abstract We present a powerful new numerical method to obtain the equilibrium states of a toroid around a black hole. The integral representation of Einstein's equations used in this paper has several advantages, one of which is that it can easily take into account the asymptotic behavior of the metric. This computational scheme can be applied to configurations with any strength of gravity of toroids and any amount of rotation of black holes. By using this scheme, we have obtained many new equilibrium configurations of general relativistic thick toroids. Highly relativistic effects of toroids on black holes or on external spacetimes have been investigated. In particular, dragging of inertial frames and tidal forces due to toroids can be clearly seen by studying the angular momentum of a black hole when the mass of the toroid is varied. Some black holes are found to have an ergoregion even if their angular momentum is zero. We find that the shape of a black hole becomes spherical when its angular momentum vanishes, even if a massive toroid exists around it. From this result, we can define nonrotating or 'spherical' black holes as those which have zero angular momentum irrespective of their angular velocity. We can, therefore, extract energy from spherical black holes, because spherical black holes can have an ergoregion. Furthermore, our schemes and results will contribute to the study of the stability of relativistic self-gravitating thick toroids by allowing the investigation of circular orbits of free particles around black holes. Publication: The Astrophysical Journal Pub Date: May 1994 DOI: 10.1086/174153 Bibcode: 1994ApJ...427..429N Keywords: Accretion Disks; Applications Of Mathematics; Black Holes (Astronomy); Equilibrium Methods; Relativity; Toroids; Angular Momentum; Angular Velocity; Circular Orbits; Gravitation; Inertial Reference Systems; Planetary Temperature; Astrophysics; ACCRETION; ACCRETION DISKS; BLACK HOLE PHYSICS; RELATIVITY full text sources ADS |