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Uncorrelated estimates of dark energy evolution

Huterer, Dragan and Cooray, Asantha (2005) Uncorrelated estimates of dark energy evolution. Physical Review D, 71 (2). Art. No.023506. ISSN 2470-0010.

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Type Ia supernova data have recently become strong enough to enable, for the first time, constraints on the time variation of the dark energy density and its equation of state. Most analyses, however, are using simple two or three-parameter descriptions of the dark energy evolution, since it is well known that allowing more degrees of freedom introduces serious degeneracies. Here we present a method to produce uncorrelated and nearly model-independent band power estimates of the equation of state of dark energy and its density as a function of redshift. We apply the method to recently compiled supernova data. Our results are consistent with the cosmological constant scenario, in agreement with other analyses that use traditional parametrizations, though we find marginal (2-sigma) evidence for w(z)<-1 at z<0.2. In addition to easy interpretation, uncorrelated, localized band powers allow intuitive and powerful testing of the constancy of either the energy density or equation of state. While we have used relatively coarse redshift binning suitable for the current set of ~150 supernovae, this approach should reach its full potential in the future, when applied to thousands of supernovae found from ground and space, combined with complementary information from other cosmological probes.

Item Type:Article
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URLURL TypeDescription
Cooray, Asantha0000-0002-3892-0190
Additional Information:© 2005 The American Physical Society. Received 8 April 2004; published 7 January 2005. We thank Eric Linder for useful comments on the manuscript. This work has been supported by the DOE at Case Western Reserve University (D.H.) and the Sherman Fairchild foundation and DOE DE-FG 03-92-ER40701 at Caltech (A.C.).
Funding AgencyGrant Number
Sherman Fairchild FoundationUNSPECIFIED
Department of Energy (DOE)DE-FG03-92-ER40701
Subject Keywords:dark energy; supernovae; equations of state; cosmology; red shift
Issue or Number:2
Record Number:CaltechAUTHORS:HUTprd05
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:5063
Deposited By: Lindsay Cleary
Deposited On:26 Sep 2006
Last Modified:02 Oct 2019 23:18

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