Recurrent Riemann-Cartan spacetimes
A Riemann-Cartan spacetime is a Lorentz-signature manifold with torsion, here assumed to be the gradient of a scalar field (``scalar torsion''). In this paper, an example of such a space-time is studied in which the curvature tensor is recurrent, covariant derivative proportional to itself. The resulting Ricci tensor is proportional to the metric, so that the space is Einstein.
scientific article; zbMATH DE number 4155398
scientific article