insu-03645730
https://insu.hal.science/insu-03645730
https://insu.hal.science/insu-03645730/document
https://insu.hal.science/insu-03645730/file/PhysRevD.89.024041.pdf
arxiv:1310.7499
doi:10.1103/PhysRevD.89.024041
[INSU] INSU - Institut National des Sciences de l'Univers
[CNRS] CNRS - Centre national de la recherche scientifique
[IAP] Institut d'Astrophysique de Paris
[SORBONNE-UNIVERSITE] Sorbonne Université
[SU-INF-2018] SORBONNE université <2018
[SU-SCIENCES] Faculté des Sciences de Sorbonne Université
[SU-TI] Sorbonne Université - Texte Intégral
[ALLIANCE-SU] Alliance Sorbonne Université
Extracting black-hole rotational energy: The generalized Penrose process
Lasota, J. -P.
Gourgoulhon, E.
Abramowicz, M.
Tchekhovskoy, A.
Narayan, R.
[SDU] Sciences of the Universe [physics]
ART
04.70.Bw
95.30.Sf
95.30.Qd
97.60.Lf
Classical black holes
Relativity and gravitation
Magnetohydrodynamics and plasmas
Black holes
General Relativity and Quantum Cosmology
Astrophysics - High Energy Astrophysical Phenomena
In the case involving particles, the necessary and sufficient condition for the Penrose process to extract energy from a rotating black hole is absorption of particles with negative energies and angular momenta. No torque at the black-hole horizon occurs. In this article we consider the case of arbitrary fields or matter described by an unspecified, general energy-momentum tensor T<SUB>μν</SUB> and show that the necessary and sufficient condition for extraction of a black hole's rotational energy is analogous to that in the mechanical Penrose process: absorption of negative energy and negative angular momentum. We also show that a necessary condition for the Penrose process to occur is for the Noether current (the conserved energy-momentum density vector) to be spacelike or past directed (timelike or null) on some part of the horizon. In the particle case, our general criterion for the occurrence of a Penrose process reproduces the standard result. In the case of relativistic jet-producing "magnetically arrested disks," we show that the negative energy and angular-momentum absorption condition is obeyed when the Blandford-Znajek mechanism is at work, and hence the high energy extraction efficiency up to ∼300% found in recent numerical simulations of such accretion flows results from tapping the black hole's rotational energy through the Penrose process. We show how black-hole rotational energy extraction works in this case by describing the Penrose process in terms of the Noether current.
2014
2022-04-24
en
Physical Review D