Gravitomagnetic vorticity generation in black hole accretion disks: a potential spatial constraint on plasma flow stability

2021 ◽  
Author(s):  
Chinmoy Bhattacharjee ◽  
David J Stark
Keyword(s):  
Black Hole ◽  
Accretion Disk ◽  
Weak Field ◽  
Generation Rate ◽  
Low Velocity ◽  
Frame Dragging ◽  
Weak Field Limit ◽  
Moving Plasma ◽  
Vorticity Generation ◽  
The Stability

Abstract We calculate the vorticity generation rate in the accretion disk near a slowly rotating black hole in the low velocity, weak-field limit of general relativity. Specifically, we find that the frame-dragging effect due to the black hole’s rotation – manifested through the gravitomagnetic field – can generate vorticity in a moving plasma in the accretion disk. The mechanism remains operational as long as the accretion disk has non-negligible vertical height and is independent of the exact thermodynamical profile of the disk. The enstrophy density generation rate, as a measure of turbulence and dissipation, is presented, which indicates that the frame-dragging effect can disrupt the stability of the disk away from the z = 0 plane.

scholarly journals Line Emission from an Accretion Disk around a Rotating Black Hole: Toward a Measurement of Frame Dragging

1997 ◽  
Vol 475 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Benjamin C. Bromley ◽  
Kaiyou Chen ◽  
Warner A. Miller
Keyword(s):  
Black Hole ◽  
Accretion Disk ◽  
Line Emission ◽  
Frame Dragging ◽  
Rotating Black Hole

scholarly journals GRAVITATIONAL LENSING IN THE WEAK FIELD LIMIT BY A BRANEWORLD BLACK HOLE

2005 ◽  
Vol 20 (32) ◽  
pp. 2487-2496 ◽  
Author(s):  
A. S. MAJUMDAR ◽  
NUPUR MUKHERJEE
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Gravitational Lensing ◽  
Cosmic Ray ◽  
Weak Field ◽  
High Energy ◽  
High Energy Particle ◽  
Field Limit ◽  
Weak Field Limit ◽  
Point Light

The existence of braneworld black holes may be of primordial origin, or may even be produced in high energy particle collisions in the laboratory and in cosmic ray showers as well. These black holes obey a modified mass–radius relationship compared to standard Schwarzschild black holes. Using the variational principle we calculate the bending angle of a light ray near the horizon of a braneworld black hole in the weak field limit. We next derive the expressions of several lensing quantities like the Einstein radius and the magnification for a point light source. These expressions are modified compared to the lensing quantities for standard Schwarzschild black holes and contain the scale of the extra dimensions.

scholarly journals Effect of Multipole Moments in the Weak Field Limit of a Black Hole Plus Halo Potential

2021 ◽  
Vol 908 (1) ◽  
pp. 74
Author(s):  
Fredy L. Dubeibe ◽  
Tareq Saeed ◽  
Euaggelos E. Zotos
Keyword(s):  
Black Hole ◽  
Weak Field ◽  
Multipole Moments ◽  
Field Limit ◽  
Weak Field Limit

scholarly journals Constraining the spacetime spin using time delay in stationary axisymmetric spacetimes

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Haotian Liu ◽  
Junji Jia
Keyword(s):  
Black Hole ◽  
Time Delay ◽  
Gravitational Lensing ◽  
Angular Position ◽  
Weak Field ◽  
Weak Field Limit ◽  
Perturbative Method ◽  
Total Travel Time ◽  
Sgr A ◽  
The Impact

AbstractTotal travel time t and time delay $$\Delta t$$ Δ t between images of gravitational lensing (GL) in the equatorial plane of stationary axisymmetric (SAS) spacetimes for null and timelike signals with arbitrary velocity are studied. Using a perturbative method in the weak field limit, t in general SAS spacetimes is expressed as a quasi-series of the impact parameter b with coefficients involving the source-lens distance $$r_s$$ r s and lens-detector distances$$r_d$$ r d , signal velocity v, and asymptotic expansion coefficients of the metric functions. The time delay $$\Delta t$$ Δ t to the leading order(s) were shown to be determined by the spacetime mass M, spin angular momentum a and post-Newtonian parameter $$\gamma $$ γ , and kinematic variables $$r_s,~r_d,~v$$ r s , r d , v and source angular position $$\beta $$ β . When $$\beta \ll \sqrt{aM}/r_{s,d}$$ β ≪ aM / r s , d , $$\Delta t$$ Δ t is dominated by the contribution linear to spin a. Modeling the Sgr A* supermassive black hole as a Kerr–Newman black hole, we show that as long as $$\beta \lesssim 1.5\times 10^{-5}$$ β ≲ 1.5 × 10 - 5 [$$^{\prime \prime }$$ ″ ], then $$\Delta t$$ Δ t will be able to reach the $$\mathcal {O}(1)$$ O ( 1 ) second level, which is well within the time resolution of current GRB, gravitational wave and neutrino observatories. Therefore measuring $$\Delta t$$ Δ t in GL of these signals will allow us to constrain the spin of the Sgr A*.

scholarly journals ENERGY DISTRIBUTION IN THE DYADOSPHERE OF A REISSNER–NORDSTRÖM BLACK HOLE IN MØLLER'S PRESCRIPTION

2006 ◽  
Vol 21 (25) ◽  
pp. 1947-1956 ◽  
Author(s):  
ELIAS C. VAGENAS
Keyword(s):  
Black Hole ◽  
Energy Distribution ◽  
Weak Field ◽  
Specific Form ◽  
Vacuum Fluctuations ◽  
Field Limit ◽  
Weak Field Limit ◽  
Momentum Distributions ◽  
Energy And Momentum ◽  
Momentum Complex

The energy and momentum distributions in the dyadosphere of a Reissner–Nordström black hole are evaluated. The Møller's energy-momentum complex is employed for this computation. The spacetime under study is modified due to the effects of vacuum fluctuations in the dyadosphere. Therefore, the corrected Reissner–Nordström black hole metric takes into account the first contribution of the weak field limit of one-loop QED. Furthermore, a comparison and a consequent connection between our results and those already existing in the literature is provided. We hypothesize that when the energy distribution is of specific form there is a relation that connects the coefficients in the Einstein's prescription with those in the Møller's prescription.

scholarly journals ENERGY DISTRIBUTION OF (2+1)-DIMENSIONAL BLACK HOLES WITH NONLINEAR ELECTRODYNAMICS

2009 ◽  
Vol 24 (34) ◽  
pp. 2777-2785 ◽  
Author(s):  
LEONARDO BALART
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Black Hole Solution ◽  
Weak Field ◽  
Nonlinear Electrodynamics ◽  
Field Limit ◽  
Energy Distributions ◽  
Weak Field Limit ◽  
Dimensional Black Hole ◽  
Black Hole Solutions

The energy distributions for a black hole solution resulting from coupling electrodynamics and gravity in (2+1) dimensions are obtained. This solution considers the correction for a (2+1) static charged black hole from the first contribution of the weak field limit of one-loop QED in (2+1) dimensions. The Einstein and Møller energy–momentum prescriptions are used to evaluate the energy distributions associated with the mentioned (2+1)-dimensional black hole and other (2+1) black hole solutions coupled with nonlinear electrodynamics. A relation that connects the coefficients of both prescriptions is established.

scholarly journals Metric-affine bumblebee gravity: classical aspects

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Adrià Delhom ◽  
J. R. Nascimento ◽  
Gonzalo J. Olmo ◽  
A. Yu. Petrov ◽  
Paulo J. Porfírio
Keyword(s):  
Physical Properties ◽  
Weak Field ◽  
The Other ◽  
Effective Theory ◽  
Field Equations ◽  
Field Limit ◽  
Weak Field Limit ◽  
Effective Metric ◽  
The Stability ◽  
Matter Fields

AbstractWe consider the metric-affine formulation of bumblebee gravity, derive the field equations, and show that the connection can be written as Levi-Civita of a disformally related metric in which the bumblebee field determines the disformal part. As a consequence, the bumblebee field gets coupled to all the other matter fields present in the theory, potentially leading to nontrivial phenomenological effects. To explore this issue we compute the post-Minkowskian, weak-field limit and study the resulting effective theory. In this scenario, we couple scalar and spinorial matter to the effective metric, and then we explore the physical properties of the VEV of the bumblebee field, focusing mainly on the dispersion relations and the stability of the resulting effective theory.

scholarly journals Magnetic Fields in Thin Accretion Disks Around Black Holes

1993 ◽  
Vol 157 ◽  
pp. 193-196
Author(s):  
R. Khanna ◽  
M. Camenzind
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Field Strength ◽  
Accretion Disk ◽  
Outer Edge ◽  
Magnetized Plasma ◽  
Poloidal Magnetic Field ◽  
Kerr Geometry ◽  
Frame Dragging ◽  
Magnetic Diffusivity

We study magnetic field topologies and magnetic field strength in a thin accretion disk around a rotating black hole. The magnetic field is assumed to enter the disk at the outer edge and is amplified in the accretion process by differential rotation. This scenario seems likely for AGN, where magnetized plasma from a molecular torus flows into an inner accretion disk.In nonideal Newtonian magnetohydrodynamics the presence of a rotating central black hole is taken into account by using the form of the Keplerian rotation law valid for Kerr geometry outside the marginally stable orbit and a boundary layer, caused by the frame dragging effect, within. In the unstable region close to the hole the turbulent timescale is much larger than the accretion timescale so that the effective magnetic diffusivity, which is large in the disk due to turbulence, is low. As a consequence the poloidal magnetic field lines cross the horizon almost radially in agreement with [1].We present stationary axisymmetric solutions of the induction equation for vanishing α-effect. Dipolar field structures are most favourable for the generation of fast jets and can effectively contribute to the heating of a corona or some X-ray source. Quadrupolar field structures may also drive jets, however the field strength is considerably lower and therefore also the energy that can be supplied into a corona or a jet.

Review of gravitomagnetic acceleration from accretion disks

2015 ◽  
Vol 30 (38) ◽  
pp. 1530029 ◽  
Author(s):  
J. Poirier ◽  
G. J. Mathews
Keyword(s):  
Black Hole ◽  
Accretion Disk ◽  
Accretion Disks ◽  
Relativistic Effect ◽  
Vertical Direction ◽  
Frame Dragging ◽  
Neutral Particles ◽  
Gravitomagnetic Field ◽  
General Relativistic ◽  
General Relativistic Effect

We review the development of the equations of gravitoelectromagnetism and summarize how the motion of the neutral masses in an accretion disk orbiting a black hole creates a general-relativistic magnetic-like (gravitomagnetic) field that vertically accelerates neutral particles near the accretion disk upward and then inward toward the axis of the accretion disk. Even though this gravitomagnetic field is not the only mechanism to produce collimated jets, it is a novel means to identify one general relativistic effect from a much more complicated problem. In addition, as the accelerated material above or below the accretion disk nears the axis with a nearly vertical direction, a frame-dragging effect twists the trajectories around the axis thus contributing to the collimation of the jet.

Sign in / Sign up

Export Citation Format

Share Document