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Title: Cosmology without cosmic variance

The growth of structures in the Universe is described by a function G that is predicted by the combination of the expansion history of the Universe and the laws of gravity within it. We examine the improvements in constraints on G that are available from the combination of a large-scale galaxy redshift survey with a weak gravitational lensing survey of background sources. We describe a new combination of such observations that in principle this yields a measure of the growth rate that is free of sample variance, i.e. the uncertainty in G can be reduced without bound by increasing the number of redshifts obtained within a finite survey volume. The addition of background weak lensing data to a redshift survey increases information on G by an amount equivalent to a 10-fold increase in the volume of a standard redshift-space distortion measurement - if the lensing signal can be measured to sub-per cent accuracy. This argues that a combined lensing and redshift survey over a common low-redshift volume of the Universe is a more powerful test of general relativity than an isolated redshift survey over larger volume at high redshift, especially as surveys begin to cover most of the available sky.
Authors:
 [1] ;  [1]
  1. Univ. of Pennsylvania, Philadelphia, PA (United States)
Publication Date:
Grant/Contract Number:
FG02-95ER40893
Type:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 416; Journal Issue: 4; Journal ID: ISSN 0035-8711
Publisher:
Royal Astronomical Society
Research Org:
Univ. of Pennsylvania, Philadelphia, PA (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; linear growth factor G; gravitational lensing; statistical; large-scale structure of universe
OSTI Identifier:
1203601

Bernstein, Gary M., and Cai, Yan -Chuan. Cosmology without cosmic variance. United States: N. p., Web. doi:10.1111/j.1365-2966.2011.19249.x.
Bernstein, Gary M., & Cai, Yan -Chuan. Cosmology without cosmic variance. United States. doi:10.1111/j.1365-2966.2011.19249.x.
Bernstein, Gary M., and Cai, Yan -Chuan. 2011. "Cosmology without cosmic variance". United States. doi:10.1111/j.1365-2966.2011.19249.x. https://www.osti.gov/servlets/purl/1203601.
@article{osti_1203601,
title = {Cosmology without cosmic variance},
author = {Bernstein, Gary M. and Cai, Yan -Chuan},
abstractNote = {The growth of structures in the Universe is described by a function G that is predicted by the combination of the expansion history of the Universe and the laws of gravity within it. We examine the improvements in constraints on G that are available from the combination of a large-scale galaxy redshift survey with a weak gravitational lensing survey of background sources. We describe a new combination of such observations that in principle this yields a measure of the growth rate that is free of sample variance, i.e. the uncertainty in G can be reduced without bound by increasing the number of redshifts obtained within a finite survey volume. The addition of background weak lensing data to a redshift survey increases information on G by an amount equivalent to a 10-fold increase in the volume of a standard redshift-space distortion measurement - if the lensing signal can be measured to sub-per cent accuracy. This argues that a combined lensing and redshift survey over a common low-redshift volume of the Universe is a more powerful test of general relativity than an isolated redshift survey over larger volume at high redshift, especially as surveys begin to cover most of the available sky.},
doi = {10.1111/j.1365-2966.2011.19249.x},
journal = {Monthly Notices of the Royal Astronomical Society},
number = 4,
volume = 416,
place = {United States},
year = {2011},
month = {10}
}