# FRW from spaces of constant cuvature

1. Jan 7, 2007

### Mike2

FRW from spaces of constant curvature

I'm reading how the Friedmann Robertson Walker metric (with its k=-1,0,+1) is derived by considering spaces of constant curvature in order to satisfy the cosmological principle that space is the same everywhere. But I'm not able to find any derivation of these metrics of constant curvature. And that's where we get k=-1,0,+1. Any help out there? Thanks.

Last edited: Jan 8, 2007
2. Jan 8, 2007

3. Jan 8, 2007

### Mike2

Thanks for the tip. I'm trying to go through it. Where did he come up with equation 2.11? What is S() in Fig 2.1? Thanks.

4. Jan 11, 2007

### quantum123

I don't seem to be able to find it.

5. Jan 20, 2007

### Mike2

The best I've been able to find is statements like the following:
"An N dimensional Riemannian space is of constant curvature if its curvature tensor obeys

$$$R_{\mu \nu \gamma \lambda } = \frac{R}{{N(N - 1)}}(g_{\mu \gamma } g_{\nu \lambda } - g_{\mu \lambda } g_{\nu \gamma } ),\,\,\,\,\,\,\,R = const.,$$$

where R/N(N-1) = $$\varepsilon\$$K-2 is called the Gaussian curvature."

Can someone show me how that calculation was derived? Or would it more appropriate to post this question to the Tensor Analysis & Differential Geometry forum? Thanks.

Last edited: Jan 20, 2007
6. Jan 21, 2007

### Hacky

7. Jan 21, 2007

### hellfire

I am sorry, when I posted the link the access was free to all chapters of the lectures.