On Dec 2, 2007 11:28 PM, Viktor T. Toth <vttoth at vttoth.com> wrote:
> I don't think there is a bug, but please feel free to check and let me know
> if you think otherwise!
For example, for the Robertson-Walker metric, it's easy to calculate
the tt component of the covariant Ricci tensor from the Riemann
curvature tensor given by ctensor. The result is 3*diff(a,t,2)/a,
where a is the scale factor. However the result given by ctensor
directly is -3*diff(a,t,2)/a. Have I made some mistakes?