- #1
binbagsss
- 1,265
- 11
I'm looking at Lecture Notes on General Relativity, Sean M. Carroll, deriving the FRW metric, and I'm a little confused with the use of eq 8.4 .
I thought instead it should be using the general form of a spherically symmetric metric, not a vacuum spherical symmetric - eq 7.13 has been derived from 8.4 by solving ##R_{uv}=0## enabling us to loose the time dependence in the function ## \beta(t,r) ## as we don't want a vacuum solution here at all?
What has enabled us to conclude ## \beta(t,r) = \beta(r) ##
Thanks in advance.
I thought instead it should be using the general form of a spherically symmetric metric, not a vacuum spherical symmetric - eq 7.13 has been derived from 8.4 by solving ##R_{uv}=0## enabling us to loose the time dependence in the function ## \beta(t,r) ## as we don't want a vacuum solution here at all?
What has enabled us to conclude ## \beta(t,r) = \beta(r) ##
Thanks in advance.