# Robertson-walker metric

## Main Question or Discussion Point

This metric is often written in an alternative form, here called the curvature normalized way. Unfortunately I can't follow how they rewrite it, could someone hint me how it is done or tell me a text where it is shown in more detail?

thanks

## Answers and Replies

Related Special and General Relativity News on Phys.org
Ich
The derivation is straightforward once you know that $$sin^{-1}$$ means arcsin there.