Petrov type I spacetime curvature: principal null vector spanning dimension
arXiv:2111.01283 · doi:10.1142/S0219887823500871
Abstract
The class of Petrov type I curvature tensors is further divided into those for which the span of the set of distinct principal null directions has dimension four (maximally spanning type I) or dimension three (nonmaximally spanning type I). Explicit examples are provided for both vacuum and nonvacuum spacetimes.
v1: 16 pages; v2: 21 pages, references added, discussion expanded; v3: 21 pages, final version matching the published one