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Title: Redshift drift in an inhomogeneous universe: averaging and the backreaction conjecture

Abstract

An expression for the average redshift drift in a statistically homogeneous and isotropic dust universe is given. The expression takes the same form as the expression for the redshift drift in FLRW models. It is used for a proof-of-principle study of the effects of backreaction on redshift drift measurements by combining the expression with two-region models. The study shows that backreaction can lead to positive redshift drift at low redshifts, exemplifying that a positive redshift drift at low redshifts does not require dark energy. Moreover, the study illustrates that models without a dark energy component can have an average redshift drift observationally indistinguishable from that of the standard model according to the currently expected precision of ELT measurements. In an appendix, spherically symmetric solutions to Einstein's equations with inhomogeneous dark energy and matter are used to study deviations from the average redshift drift and effects of local voids.

Authors:
;  [1]
  1. Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)
Publication Date:
OSTI Identifier:
22525081
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2016; Journal Issue: 01; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; COSMIC DUST; COSMOLOGICAL MODELS; COSMOLOGY; EINSTEIN FIELD EQUATIONS; MATHEMATICAL SOLUTIONS; NONLUMINOUS MATTER; RED SHIFT; SPHERICAL CONFIGURATION; STANDARD MODEL; SYMMETRY; UNIVERSE

Citation Formats

Koksbang, S.M., and Hannestad, S., E-mail: koksbang@phys.au.dk, E-mail: sth@phys.au.dk. Redshift drift in an inhomogeneous universe: averaging and the backreaction conjecture. United States: N. p., 2016. Web. doi:10.1088/1475-7516/2016/01/009.
Koksbang, S.M., & Hannestad, S., E-mail: koksbang@phys.au.dk, E-mail: sth@phys.au.dk. Redshift drift in an inhomogeneous universe: averaging and the backreaction conjecture. United States. doi:10.1088/1475-7516/2016/01/009.
Koksbang, S.M., and Hannestad, S., E-mail: koksbang@phys.au.dk, E-mail: sth@phys.au.dk. 2016. "Redshift drift in an inhomogeneous universe: averaging and the backreaction conjecture". United States. doi:10.1088/1475-7516/2016/01/009.
@article{osti_22525081,
title = {Redshift drift in an inhomogeneous universe: averaging and the backreaction conjecture},
author = {Koksbang, S.M. and Hannestad, S., E-mail: koksbang@phys.au.dk, E-mail: sth@phys.au.dk},
abstractNote = {An expression for the average redshift drift in a statistically homogeneous and isotropic dust universe is given. The expression takes the same form as the expression for the redshift drift in FLRW models. It is used for a proof-of-principle study of the effects of backreaction on redshift drift measurements by combining the expression with two-region models. The study shows that backreaction can lead to positive redshift drift at low redshifts, exemplifying that a positive redshift drift at low redshifts does not require dark energy. Moreover, the study illustrates that models without a dark energy component can have an average redshift drift observationally indistinguishable from that of the standard model according to the currently expected precision of ELT measurements. In an appendix, spherically symmetric solutions to Einstein's equations with inhomogeneous dark energy and matter are used to study deviations from the average redshift drift and effects of local voids.},
doi = {10.1088/1475-7516/2016/01/009},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 01,
volume = 2016,
place = {United States},
year = 2016,
month = 1
}
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