English

Non existence of closed and bounded null geodesics in Kerr spacetimes

Differential Geometry 2025-04-28 v3 General Relativity and Quantum Cosmology Mathematical Physics math.MP

Abstract

The Kerr-star spacetime is the extension over the horizons and in the negative radial region of the slowly rotating Kerr black hole. It is known that below the inner horizon, there exist both timelike and null (lightlike) closed curves. Nevertheless, we prove that null geodesics can be neither closed nor even contained in a compact subset of the Kerr-star spacetime.

Keywords

Cite

@article{arxiv.2308.09631,
  title  = {Non existence of closed and bounded null geodesics in Kerr spacetimes},
  author = {Giulio Sanzeni},
  journal= {arXiv preprint arXiv:2308.09631},
  year   = {2025}
}

Comments

We extend the previous result ("non existence of closed null geodesics in Kerr spacetimes") proving that the null geodesics cannot be contained in a compact subset of the Kerr-star spacetime