Null conformal Killing-Yano tensors and Birkhoff theorem

TL;DR

This paper investigates spacetimes with null conformal Killing-Yano tensors, exploring their properties, relation to Killing vectors, and generalizing Birkhoff's theorem for null orbit cases.

Contribution

It extends the understanding of null conformal Killing-Yano tensors and generalizes Birkhoff's theorem for null orbits, building on previous non-null case studies.

Findings

Null conformal Killing-Yano tensors define special spacetime symmetries.

The divergence of these tensors yields Killing vectors.

Generalization of Birkhoff's theorem for null orbit scenarios.

Abstract

We study the space-times admitting a null conformal Killing-Yano tensor whose divergence defines a Killing vector. We analyze the similitudes and differences with the recently studied non null case (Gen. Relativ. Grav. (2015) {\bf 47} 1911). The results by Barnes concerning the Birkhoff theorem for the case of null orbits are analyzed and generalized.