Quasi-regular singularities based on null planes
We examine quasi-regular singularities that take the form of invariant two-dimensional null planes in Minkowski space-time, thus extending earlier studies of ''conical'' singularities based on timelike and spacelike planes. The result is described in terms of a deficit parameter. We also examine the form of the Riemann curvature tensor at the singularity.
scientific article; zbMATH DE number 4009275