Geodesic-light-cone coordinates and the Bianchi I spacetime

Journal Article · Wed Jun 01 04:00:00 EDT 2016 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2016/06/008· OSTI ID:22679687

Fleury, Pierre ^[1]; Nugier, Fabien ^[2]; Fanizza, Giuseppe ^[3]

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1. Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town (South Africa)
2. Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan, R.O.C. (China)
3. Dipartimento di Fisica, Università di Bari, Via G. Amendola 173, 70126 Bari (Italy)

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.

• OSTI ID: 22679687
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 06 Vol. 2016; ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANISOTROPY
COORDINATES
COSMOLOGICAL MODELS
COSMOLOGY
DEGREES OF FREEDOM
GRAVITATIONAL LENSES
ISOTROPY
LIGHT CONE
LIGHT TRANSMISSION
RED SHIFT
SURFACES
UNIVERSE
VISIBLE RADIATION