Talk:Projective vector field

Need to define projectives on any manifold first then specialise to spacetimes. ---Mpatel (talk) 13:12, August 28, 2005 (UTC)

Well, you need something that fixes the geodesic structure, so generalization to (semi) Riemannian manifolds is straight forward, done. [melli]146.186.134.176 (talk) 00:42, 15 February 2008 (UTC)[reply]

Given a vector field $X=(X^{a})$ on a semi Riemannian manifold, what is $X_{ab}$ ? Is it related to your $h_{ab}$ or $F_{ab}$ ? if it were just $X_{a;b}$ then $\psi$ would be 0, right? [melli] 146.186.134.176 (talk) 00:33, 15 February 2008 (UTC)[reply]

I hope the dimensional estimates for the algebras (which are clearly local) do not depend on the signature of the metric. [melli]146.186.134.176 (talk) 01:06, 15 February 2008 (UTC)[reply]