Observation angles, Fermi coordinates, and the Geodesic-Light-Cone gauge
arXiv:1812.03671 · doi:10.1088/1475-7516/2019/01/004
Abstract
We show that the angular directions locally measured by a static geodesic observer in a generic cosmological background and expressed in the system of Fermi Normal Coordinates always coincide with those expressed in the Geodesic-Light-Cone (GLC) gauge, up to a local transformation which exploits the residual gauge freedom of the GLC coordinates. This is not the case for other gauges - like, for instance, the synchronous and longitudinal gauge - commonly used in the context of observational cosmology. We also make an explicit proposal for the GLC gauge-fixing condition that ensures a full identification of its angles with the observational ones.
arXiv comment14 pages, version accepted for publication on JCAP
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Cited by in corpus (7)
- Generalized covariant prescriptions for averaging cosmological observables
- Cosmological Perturbations and Invariant Observables in Geodesic Lightcone Coordinates
- Cutting out the cosmological middle man: General Relativity in the light-cone coordinates
- Rotation of the CMB polarisation by foreground lensing
- A Light-Cone Approach to Higher-Order Cosmological Observables
- A Simple, Exact Formulation of Number Counts in the Geodesic-Light-Cone Gauge
- The gauge invariant cosmological Jacobi map from weak lensing at leading order