Tagged Questions
5
votes
0answers
91 views
Positivity of Total Gravitational Energy in GR
I read the following statement in the introduction to an article:
Over the last 30 years, one of the greatest achievements in classical
general relativity has certainly been the proof of the ...
1
vote
1answer
130 views
Where did Karl Schwarzschild derived his solution?
Does anyone know more about circumstances of Karl Schwarzschild at the Russian front in 1915 where he allegedly derived his famous solution of the Einstein equations (describing a black hole)? Sources ...
1
vote
1answer
77 views
Ultracold atoms and General theory of Relativty
I am looking for good reviews for the subject of Ultracold atoms and it's application in test of General theory of relativity. I am planning to pick up this topic as a semester project, can somebody ...
4
votes
1answer
187 views
Dimensional reduction and Schwarzschild solution
It is well-known that, given a Killing vector $\xi_\mu$ for a metric, this can be dimensionally reduced. This is exactly the case of the Schwarzschild solution due to the rotational symmetry. This ...
3
votes
2answers
182 views
Linearizing Gravity to ${\cal O}(h^3)$
I've seen the action of linearized gravity in many places. We basically have
$${\cal L} \sim \frac{1}{G_N}\left( - \frac{1}{2}h^{\alpha\beta} \Box h_{\alpha\beta} + \frac{1}{4} h \Box h + {\cal ...
1
vote
0answers
61 views
Reference request: FLRW with k>0, dust, and positive cosmological constant
The exact solution representing a FLRW universe with $k>0$ and dust (p=0), and $\Lambda=0$, is described by a cycloid. What is the exact solution for dust, in the presence of a positive ...
0
votes
0answers
104 views
Time reversal symmetry and reversal of vectors
Firstly: I have been told that under time reversal transformations, i.e. $t\rightarrow -t$, vector fields must change sign. Why is this? I haven't found this in the literature, any references?
...
3
votes
2answers
373 views
Where do I start with Non-Euclidean Geometry?
I've been trying to grok General Relativity for a while now, and I've been having some trouble. Many physics textbooks gloss over the subject with an "it's too advanced for this medium", and many ...
0
votes
2answers
348 views
Abstract Algebra in Relativity and Cosmology?
Is Abstract Algebra useful in theoretical Relativity and/or Cosmology? If so can anyone give me some examples or point me towards a good book with that emphasis if it is one?
Thanks in advance.
5
votes
3answers
89 views
Analyticity and Causality in Relativity
A few weeks ago at a conference a speaker I was listening to made a comment to the effect that a function (let's say scalar) cannot be analytic because otherwise it would violate causality. He didn't ...
7
votes
1answer
88 views
Fourier Methods in General Relativity
I am looking for some references which discuss Fourier transform methods in GR. Specifically supposing you have a metric $g_{\mu \nu}(x)$ and its Fourier transform $\tilde{g}_{\mu \nu}(k)$, what does ...
5
votes
2answers
511 views
Why is spacetime near a quantum black hole approximately AdS?
In this link, one of the answers contains the statement
If you examine the space-time near a finite area quantum black hole,
you will see an approximate AdS space.
Presumably "approximate" ...
4
votes
4answers
844 views
That 10km/day error predicted if GPS satellite clocks not corrected for relativity
Some authorities have stated publicly and without explanation that if the theories of Special and General Relativity were not taken into account in the design of the GPS (by building the satellite ...
4
votes
0answers
99 views
K3 gravitational instanton
Could you please recommend a sufficiently elementary introduction to K3 gravitational instanton in general relativity and the problem of finding its explicit form?
Under 'sufficiently elementary' I ...
4
votes
1answer
390 views
When will the Hubble volume coincide with the volume of the observable Universe?
The Hubble volume is the volume that corresponds to objects so far from the Earth that the space between us and them is expanding faster than the speed of light. (I.e. objects outside this volume ...
