Definition
A manifold $M$ together with a pseudo-Riemannian metric.
$\blacksquare$
They are, in some sense, metric spaces: we can measure lengths.
A particular case are the Riemannian manifolds.
We can compute volumes in a natural way, and therefore we have a distinguished volume form in it.
It can be interpreted as a Cartan geometry.
________________________________________
________________________________________
________________________________________
Author of the notes: Antonio J. Pan-Collantes
INDEX: