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Title: Redshift sensitivities of dark energy surveys

Abstract

Great uncertainty surrounds dark energy, both in terms of its physics, and the choice of methods by which the problem should be addressed. Here we quantify the redshift sensitivities offered by different techniques. We focus on the three methods most adept at constraining w, namely, supernovae, cosmic shear, and baryon oscillations. For each we provide insight into the family of w(z) models which are permitted for a particular constraint on either w=w{sub 0} or w=w{sub 0}+w{sub a}(1-a). Our results are in the form of 'weight functions', which describe the fitted model parameters as a weighted average over the true functional form. For example, we find the recent best-fit from the Supernovae Legacy Survey (w=-1.023) corresponds to the average value of w(z) over the range 0<z<0.4. Whilst there is a strong dependence on the choice of priors, each cosmological probe displays distinctive characteristics in their redshift sensitivities. In the case of proposed future surveys, a SNAP-like supernova survey probes a mean redshift of z{approx}0.3, with baryon oscillations and cosmic shear at z{approx}0.6. If we consider the evolution of w, sensitivities shift to slightly higher redshift. Finally, we find that the weight functions may be expressed as a weighted average of themore » popular 'principal components'.« less

Authors:
 [1];  [2]
  1. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
  2. Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
Publication Date:
OSTI Identifier:
20782862
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 8; Other Information: DOI: 10.1103/PhysRevD.73.083001; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; BARYONS; COSMOLOGY; NONLUMINOUS MATTER; OSCILLATIONS; PROBES; RED SHIFT; SENSITIVITY; SHEAR; SUPERNOVAE; WEIGHTING FUNCTIONS

Citation Formats

Simpson, Fergus, and Bridle, Sarah. Redshift sensitivities of dark energy surveys. United States: N. p., 2006. Web. doi:10.1103/PHYSREVD.73.083001.
Simpson, Fergus, & Bridle, Sarah. Redshift sensitivities of dark energy surveys. United States. doi:10.1103/PHYSREVD.73.083001.
Simpson, Fergus, and Bridle, Sarah. Sat . "Redshift sensitivities of dark energy surveys". United States. doi:10.1103/PHYSREVD.73.083001.
@article{osti_20782862,
title = {Redshift sensitivities of dark energy surveys},
author = {Simpson, Fergus and Bridle, Sarah},
abstractNote = {Great uncertainty surrounds dark energy, both in terms of its physics, and the choice of methods by which the problem should be addressed. Here we quantify the redshift sensitivities offered by different techniques. We focus on the three methods most adept at constraining w, namely, supernovae, cosmic shear, and baryon oscillations. For each we provide insight into the family of w(z) models which are permitted for a particular constraint on either w=w{sub 0} or w=w{sub 0}+w{sub a}(1-a). Our results are in the form of 'weight functions', which describe the fitted model parameters as a weighted average over the true functional form. For example, we find the recent best-fit from the Supernovae Legacy Survey (w=-1.023) corresponds to the average value of w(z) over the range 0<z<0.4. Whilst there is a strong dependence on the choice of priors, each cosmological probe displays distinctive characteristics in their redshift sensitivities. In the case of proposed future surveys, a SNAP-like supernova survey probes a mean redshift of z{approx}0.3, with baryon oscillations and cosmic shear at z{approx}0.6. If we consider the evolution of w, sensitivities shift to slightly higher redshift. Finally, we find that the weight functions may be expressed as a weighted average of the popular 'principal components'.},
doi = {10.1103/PHYSREVD.73.083001},
journal = {Physical Review. D, Particles Fields},
number = 8,
volume = 73,
place = {United States},
year = {Sat Apr 15 00:00:00 EDT 2006},
month = {Sat Apr 15 00:00:00 EDT 2006}
}