Light-cone averaging in cosmology: formalism and applications

Journal Article · Fri Jul 01 00:00:00 EDT 2011 · Journal of Cosmology and Astroparticle Physics

DOI:https://doi.org/10.1088/1475-7516/2011/07/008· OSTI ID:22277769

Gasperini, M. ^[1]; Marozzi, G.; Veneziano, G. ^[2]

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1. Dipartimento di Fisica, Università di Bari, Via G. Amendola 173, 70126 Bari, Italy, (Italy)
2. Collège de France, 11 Place M. Berthelot, 75005 Paris (France)

We present a general gauge invariant formalism for defining cosmological averages that are relevant for observations based on light-like signals. Such averages involve either null hypersurfaces corresponding to a family of past light-cones or compact surfaces given by their intersection with timelike hypersurfaces. Generalized Buchert-Ehlers commutation rules for derivatives of these light-cone averages are given. After introducing some adapted ''geodesic light-cone'' coordinates, we give explicit expressions for averaging the redshift to luminosity-distance relation and the so-called ''redshift drift'' in a generic inhomogeneous Universe.

• OSTI ID: 22277769
• Journal Information: Journal of Cosmology and Astroparticle Physics, Vol. 2011, Issue 07; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
COORDINATES
COSMOLOGY
DISTANCE
GAUGE INVARIANCE
GEODESICS
LIGHT CONE
LUMINOSITY
RED SHIFT
UNIVERSE
VISIBLE RADIATION