All Questions
5
questions
0
votes
0
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73
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Energy conservation, photon, distance
From Weinberg 1972 Gravitation and Cosmology Principles, when discussing the luminosity distance, he talked about due to light wavelength being stretched as well as time interval stretched, in the &...
- 161
3
votes
1
answer
134
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Distance in Hubble law vs special relativity
Came across this very informative website https://astro.ucla.edu/~wright/cosmo_02.htm , and it has the following two diagrams. I'm having trouble figuring out why "But the Hubble law distance $D_{...
- 161
1
vote
1
answer
477
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Distances in cosmology
I want to make sure that I understand the different distance measures is cosmology.
To do that I consider the FLRW metric:
$$ ds^2=dt^2-R(t)^2\left(\frac{dr^2}{1-kr^2}+r^2d\theta^2+r^2\sin^2\theta d\...
user255856
1
vote
2
answers
570
views
Proper distance in cosmology
If considering two galaxies $\mathcal{A}$ and $\mathcal{B}$ being separated by $d$ ($d$ being the comoving distance) and light is emmited from $\mathcal{A}$ at time $t_1$ and that light is received to ...
- 101
0
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0
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120
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Is there a difference between horizon and comoving distances?
I wonder if there a difference between horizon and comoving distances in cosmology ?
I mean both correspond to a null geodesic $(ds^2=0)$ right ?
- 161