Lightcone observables and gaugeinvariance in the geodesic lightcone formalism
Abstract
The remarkable properties of the geodesic lightcone (GLC) coordinates allow analytic expressions for the lightcone observables, providing a new nonperturbative way for calculating the effects of inhomogeneities in our Universe. However, the gaugeinvariance of these expressions in the GLC formalism has not been shown explicitly. Here we provide this missing part of the GLC formalism by proving the gaugeinvariance of the GLC expressions for the lightcone observables, such as the observed redshift, the luminosity distance, and the physical area and volume of the observed sources. Our study provides a new insight on the properties of the GLC coordinates and it complements the previous work by the GLC collaboration, leading to a comprehensive description of light propagation in the GLC representation.
 Authors:
 Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, Winterthurerstrasse 190, CH8057, Zürich (Switzerland)
 Publication Date:
 OSTI Identifier:
 22676179
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 06; Other Information: Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMPUTERIZED SIMULATION; DISTANCE; GAUGE INVARIANCE; LIGHT CONE; LUMINOSITY; PERTURBATION THEORY; RED SHIFT; UNIVERSE
Citation Formats
Scaccabarozzi, Fulvio, and Yoo, Jaiyul, Email: fulvio@physik.uzh.ch, Email: jyoo@physik.uzh.ch. Lightcone observables and gaugeinvariance in the geodesic lightcone formalism. United States: N. p., 2017.
Web. doi:10.1088/14757516/2017/06/007.
Scaccabarozzi, Fulvio, & Yoo, Jaiyul, Email: fulvio@physik.uzh.ch, Email: jyoo@physik.uzh.ch. Lightcone observables and gaugeinvariance in the geodesic lightcone formalism. United States. doi:10.1088/14757516/2017/06/007.
Scaccabarozzi, Fulvio, and Yoo, Jaiyul, Email: fulvio@physik.uzh.ch, Email: jyoo@physik.uzh.ch. Thu .
"Lightcone observables and gaugeinvariance in the geodesic lightcone formalism". United States.
doi:10.1088/14757516/2017/06/007.
@article{osti_22676179,
title = {Lightcone observables and gaugeinvariance in the geodesic lightcone formalism},
author = {Scaccabarozzi, Fulvio and Yoo, Jaiyul, Email: fulvio@physik.uzh.ch, Email: jyoo@physik.uzh.ch},
abstractNote = {The remarkable properties of the geodesic lightcone (GLC) coordinates allow analytic expressions for the lightcone observables, providing a new nonperturbative way for calculating the effects of inhomogeneities in our Universe. However, the gaugeinvariance of these expressions in the GLC formalism has not been shown explicitly. Here we provide this missing part of the GLC formalism by proving the gaugeinvariance of the GLC expressions for the lightcone observables, such as the observed redshift, the luminosity distance, and the physical area and volume of the observed sources. Our study provides a new insight on the properties of the GLC coordinates and it complements the previous work by the GLC collaboration, leading to a comprehensive description of light propagation in the GLC representation.},
doi = {10.1088/14757516/2017/06/007},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 06,
volume = 2017,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2017},
month = {Thu Jun 01 00:00:00 EDT 2017}
}

The remarkable properties of the recently proposed geodesic lightcone (GLC) gauge allow to explicitly solve the geodesicdeviation equation, and thus to derive an exact expression for the Jacobi map J{sup A}{sub B}(s,o) connecting a generic source s to a geodesic observer o in a generic space time. In this gauge J{sup A}{sub B} factorizes into the product of a local quantity at s times one at o, implying similarly factorized expressions for the area and luminosity distance. In any other coordinate system J{sup A}{sub B} is simply given by expressing the GLC quantities in terms of the corresponding ones inmore »

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