Questions tagged [kerr-metric]
The Kerr metric describes the geometry of empty spacetime around a rotating uncharged axially-symmetric black hole.
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What determines the stability of a Kerr black hole under perturbations?
Does anybody know what factors influence the stability of a Kerr black hole when small perturbations are applied? While I know the Kerr–Newman solution is generally considered to be linearly stable, I ...
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Kerr infinite redshift surface: length of meridian less than equator
In Kerr spacetime geometry, consider a surface defined by $t = t_0$ (a constant) and the infinite redshift surface $r = r_{S\pm}$. (Not the event horizon)
Kerr geometry:
$$
d{s}^2 = -d{t}^2 + \frac{\...
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Asymptotic flatness of Kerr metric
I am following Geometry and physics of Black Holes by Eric Gourgoulhon https://share.google/zA50kChCq9PE75bnT
At page#322-323 he said for Boyer Lindquist metric
The spacetime has two asymptotically ...
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Would you see the entire past history of the universe when falling into a charged/rotating black hole?
Would you see the entire past history of the universe when falling into a charged/rotating black hole as you approached the inner event horizon?
I’ve read multiple sources here that contradict each ...
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What would the Negative $𝑟$-Coordinate Region of the Kerr Metric look like from afar?
In the Kerr Metric there's a Negative $𝑟$-Coordinate Region on the other side of the ring singularity.
If you went through the ring, continued on and then looked back, how would it appear? What would ...
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Would the metric of a rotating Universe have a 'ring' singularity at the Big Bang?
Rotating black holes have ring singularities at their center per the Kerr metric. The FRW metric has a point singularity at the Big Bang. If instead of being a non-rotating FRW spacetime, the ...
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Define surface gravity for Kerr Black Hole
Caroll defined surface gravity at page #246 as :
In a static, asymptotically flat spacetime, the surface gravity is the acceleration of a static observer near the horizon, as measured by a static ...
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Why we need Hypersurfaces of constant coordinate $t$ in defining ZAMO?
Hypersurfaces of constant coordinate $t$ frequently occur in General Relativity. I am having trouble in understanding the importance and concept of these hypersurfaces.
Firstly, we say in ...
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Doubt in angular momentum of ZAMO
We say Zero Angular Momentum Observers (ZAMOs) are observers having zero angular momentum at infinity but when they approach to Kerr Black Hole, they gain some angular velocity due to frame dragging.
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The Newman-Janis Algorithm and solutions to dynamical fields
The Newman-Janis algorithm is a trick that generates rotating axisymmetric solutions to the Einstein field equations, given a non-rotating, static, spherically symmetric "seed" metric. The ...
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What is twisting of subspace of tangent space?
Wald in B.3 Frobenius theorem at page#435 wrote
If $\dim W > 1$, it is possible for the $W$-planes to "twist around" so that integral submanifolds cannot be found
This concept requires ...
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Why is it so that the maximum rotational kinetic energy that a rotating black hole can have is 29% of its rest mass?
I am currently in high school and I have very basic understanding of relativity and rotational mechanics. Is there a reason why a rotating black hole has maximally only 29% of its rest mass energy as ...
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Contradiction when calculating orbital velocity around a rotating black hole seen by a distant stationary observer
From many other questions posted here and in other forums about orbits around black holes, I arrived at a contradiction. From these parameters:
$$a = 1.00 - 1.33\times10^{-14}$$
$$M = 10^8 M_\odot$$
$...
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What is the orbital period of Miller's planet around Gargantua in the movie Interstellar?
In the movie Interstellar, there is a planet called Miller that orbits a supermassive black hole (Gargantua) so close that each hour is 7 years on Earth.
Miller's planet orbits Gargantua at ISCO with ...
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Gravity in the Negative $r$-Coordinate Region of the Kerr Metric
I've read a few questions about the Kerr metric, and the ring singularity that the math discusses behind the inner Cauchy horizon. While we should be careful in taking anything past the Cauchy horizon ...
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