On a property of conformal spacetimes (Q1062298)

The authors investigate spacetimes having no time-like isometry. They use a generalization of Carter's circular metrics, having at least one time- like and one space-like isometry. It is proven that a conformal time-like Killing vector depends only on time, provided the circular metrics are extended to spacetimes with generalized circular metrics in order to admit such a Killing vector.