Slowly balding black holes

Journal Article · Sat Oct 15 04:00:00 EDT 2011 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.84.084019· OSTI ID:21607903

Lyutikov, Maxim; McKinney, Jonathan C ^[1]

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1. Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana 47907-2036 (United States)

The 'no-hair' theorem, a key result in general relativity, states that an isolated black hole is defined by only three parameters: mass, angular momentum, and electric charge; this asymptotic state is reached on a light-crossing time scale. We find that the no-hair theorem is not formally applicable for black holes formed from the collapse of a rotating neutron star. Rotating neutron stars can self-produce particles via vacuum breakdown forming a highly conducting plasma magnetosphere such that magnetic field lines are effectively ''frozen in'' the star both before and during collapse. In the limit of no resistivity, this introduces a topological constraint which prohibits the magnetic field from sliding off the newly-formed event horizon. As a result, during collapse of a neutron star into a black hole, the latter conserves the number of magnetic flux tubes N{sub B}=e{Phi}{sub {infinity}}/({pi}c({h_bar}/2{pi})), where {Phi}{sub {infinity}}{approx_equal}2{pi}{sup 2}B{sub NS}R{sub NS}{sup 3}/(P{sub NS}c) is the initial magnetic flux through the hemispheres of the progenitor and out to infinity. We test this theoretical result via 3-dimensional general relativistic plasma simulations of rotating black holes that start with a neutron star dipole magnetic field with no currents initially present outside the event horizon. The black hole's magnetosphere subsequently relaxes to the split-monopole magnetic field geometry with self-generated currents outside the event horizon. The dissipation of the resulting equatorial current sheet leads to a slow loss of the anchored flux tubes, a process that balds the black hole on long resistive time scales rather than the short light-crossing time scales expected from the vacuum no-hair theorem.

• OSTI ID: 21607903
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 8 Vol. 84; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR MOMENTUM
ASYMPTOTIC SOLUTIONS
BLACK HOLES
DIPOLES
ELECTRIC CHARGES
FIELD THEORIES
GENERAL RELATIVITY THEORY
MAGNETIC FIELDS
MAGNETIC FLUX
MASS
MATHEMATICAL SOLUTIONS
MATHEMATICS
MULTIPOLES
NEUTRON STARS
PLASMA
RELATIVISTIC PLASMA
RELATIVITY THEORY
SIMULATION
STARS
THREE-DIMENSIONAL CALCULATIONS
TOPOLOGY