All Questions
19
questions
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Where is the mass in a Black Hole without a "central" curvature singularity?
Not all black holes have a curvature singularity at their center (an example). But in principle, I thought that the curvature singularity was a direct result of the fact that the mass is concentrated ...
- 770
26
votes
10
answers
13k
views
How do black holes move if they are just regions in spacetime?
If black holes are just regions of spacetime, how can black holes even move? When matter moves through spacetime, it bends the spacetime around it, but if black holes are just regions of spacetime, ...
- 403
6
votes
1
answer
262
views
How to find that there is a conical singularity in the BTZ black hole?
Considering a non-rotating and non-charged 2+1 dimensional black hole, known as the BTZ black hole which obtained by adding a negative cosmological constant $\Lambda=-\frac{1}{l^2},l\ne0$ to the ...
1
vote
2
answers
173
views
How do black holes infinitely bend space-time when the bending is mass dependent and not density dependent?
According to Einstein, mass bends the fabric of space-time. And nothing in the universe has infinite mass to infinitely bend space-time. So how do remnants of supermassive stars, i.e black holes ...
- 49
4
votes
0
answers
44
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Eigenvalues of the geodesic deviation equation, curvature invariants, and singularities
The geodesic deviation equation tells us what tidal forces freely falling observers experience in a local Lorentz reference frame. The tidal deformation tensor is
$$E^{\alpha}_{\gamma}=R^{\alpha}_{\...
- 572
5
votes
2
answers
401
views
What curves spacetime in Schwarzschild metric? [duplicate]
I understand that the Schwarzschild solution is valid in the outside region of a massive object, with no other masses involved. Therefore the energy-momentum tensor is 0. But then: what curves space? ...
- 157
24
votes
3
answers
5k
views
If black holes are just empty vacuum of space inside, then what causes the curvature?
I have read this question:
The fundamental confusion many have about black holes is thinking that they are discrete "things" surrounded by horizons and other phenomena. But they are ...
- 29k
1
vote
0
answers
119
views
Non-Vacuum Solutions for Black Hole Interiors
Everything I read about black holes—discussions using Penrose diagrams and Kruskal coordinates, etc.—seems to be based on vacuum solutions to EFE. Sometimes it’s said that all trajectories entering a ...
- 41
0
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0
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52
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Derivation of the Schwarzschild solution [duplicate]
For the Derivation of the Schwarzschild solution my Professor use:
$R_{\mu\nu} = 0$ since we are in vacuum.
I see that we are in vacuum, but we assume a mass at point $r = 0$.
Thus, the curvature is ...
- 339
1
vote
1
answer
140
views
Hawking radiation and the removal of singularities
Using QFT in curved spacetime, Hawking was able to show that black holes evaporate. Whilst this has never been observered, the commonly excepted statement is that black holes continually radiate until ...
- 558
1
vote
1
answer
476
views
Roger Penrose's conformal cyclic cosmology (CCC)
Does the Weyl curvature tensor $C$ of the black hole singularity in the conformal cyclic cosmology diverge to infinity unlike the Big Bang (C = 0)?
- 61
0
votes
1
answer
134
views
Why spacetime fabric don't tears due to mass of heavy black hole?
In GR, All objects create curvatures in the space-time fabric. Why space-time fabric doesn't tear due to the mass of a heavy black hole? What is it made of?
2
votes
1
answer
174
views
Can a curvature singularity (i.e. BH), as defined in terms of geodesic incompleteness, actually exist in nature?
A curvature invariant is a scalar representation of curvature derived from a curvature tensor. The classic example is the Kretschmann scalar derived from the Riemann curvature, where $K=R_{μνλρ}R^{...
- 61
0
votes
1
answer
277
views
Are the actual singularities with geodesic incompleteness the same as curvature singularities?
Types of singularities include curvature singularities and conical singularities. So, for a curvature singularity(black hole) with geodesic incompleteness, is it the same as a physical singularity? If ...
- 61
-2
votes
1
answer
100
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General Theory of Relativity [duplicate]
Why is General Theory of Relativity not applicable in the singularity of Black Hole?
