The variables used in general relativity to describe the shape of spacetime. If your question is about metric units, use the tag "units", and/or "si-units" if it is about the SI system specifically.
12
votes
3answers
97 views
What is meant when it is said that the universe is homogeneous and isotropic?
It is sometimes said that the universe is homogeneous and isotropic. What is meant by each of these descriptions? Are they mutually exclusive, or does one require the other? And what implications rise ...
4
votes
3answers
130 views
How do you tell if a metric is curved?
I was reading up on the Kerr metric (from Sean Carroll's book) and something that he said confused me.
To start with, the Kerr metric is pretty messy, but importantly, it contains two constants - ...
0
votes
2answers
49 views
Changing the scalar curvature (k = 0,+1,-1) with coordinate transformations?
I would like to prove that I can (or can't) change curvature of space, k = 0,+1,-1, via general coordinate transformations, which in principle can mix space and time coordinates together.
-2
votes
0answers
77 views
How to calculate a scalar curvature fast? [closed]
Let's have a metric tensor
$$ g^{\alpha \beta} = \frac{1}{\left( 1 + \frac{ct}{R} \right)^{2}}\begin{bmatrix} \frac{1 - \frac{r^{2}}{R^{2}}}{\left(1 + \frac{ct}{R}\right)^{2}} & ...
