English

Geodesic-light-cone coordinates and the Bianchi I spacetime

General Relativity and Quantum Cosmology 2016-06-09 v2 Cosmology and Nongalactic Astrophysics

Abstract

The geodesic-light-cone (GLC) coordinates are a useful tool to analyse light propagation and observations in cosmological models. In this article, we propose a detailed, pedagogical, and rigorous introduction to this coordinate system, explore its gauge degrees of freedom, and emphasize its interest when geometric optics is at stake. We then apply the GLC formalism to the homogeneous and anisotropic Bianchi I cosmology. More than a simple illustration, this application (i) allows us to show that the Weinberg conjecture according to which gravitational lensing does not affect the proper area of constant-redshift surfaces is significantly violated in a globally anisotropic universe; and (ii) offers a glimpse into new ways to constrain cosmic isotropy from the Hubble diagram.

Keywords

Cite

@article{arxiv.1602.04461,
  title  = {Geodesic-light-cone coordinates and the Bianchi I spacetime},
  author = {Pierre Fleury and Fabien Nugier and Giuseppe Fanizza},
  journal= {arXiv preprint arXiv:1602.04461},
  year   = {2016}
}

Comments

27 pages, 5 figures, v2 matches published version

R2 v1 2026-06-22T12:49:55.549Z