Friedmann equation

1. Aug 20, 2006

blumfeld0

Hi does anyone know a website or paper where the friedmann equation is derived from the robertson walker metric?
it should have the calculation of atleast a few of the christoffel symbols etc

thanks

blumfeld

2. Aug 20, 2006

Parlyne

The Friedmann equation can't be derived from the RW metric. It is a constraint on that metric, which is derived from the GR field equations. In other words, you can't derive it wityout the stress-energy tensor.

3. Aug 20, 2006

renerob

You may be interested in reading Relativity Demystified by David McMahon. On page 161 the following problem is worked out: Consider the Robertson-Walker metric and suppose we take the Einstein equation with nonzero constant, find the Friedman equations.

4. Aug 21, 2006

blumfeld0

Hello Thank you for the reply
So the friedmann equation is a constraint on the metric derived from the stress energy tensor
what specific stress energy tensor is used? just the diagonal
{-rho, p, p ,p }?
also are theere any websites that have the derivation of this constraint equation from einsteins field equations>?
i will also try to check out the book you recommended
thanks!