A Null Geodesic Orbit Space Whose Null Orbits Require a Reparametrization

Calvaruso, Giovanni; Zdeněk, Dušek

doi:10.7546/giq-9-2008-167-174

VOL. 9 | 2008 A Null Geodesic Orbit Space Whose Null Orbits Require a Reparametrization

Giovanni Calvaruso, Dušek Zdeněk

Editor(s) Ivaïlo M. Mladenov

Geom. Integrability & Quantization, 2008: 167-174 (2008) DOI: 10.7546/giq-9-2008-167-174

Abstract

We exhibit an example of a homogeneous Lorentzian manifold $G/H$ whose homogeneous geodesics form just the light-cone and a hyperplane in the tangent space. For all light-like homogeneous geodesics, the natural parameter of the orbit is not the affine parameter of the geodesic.