Huterer, Dragan and Cooray, Asantha (2005) Uncorrelated estimates of dark energy evolution. Physical Review D, 71 (2). Art. No.023506. ISSN 0556-2821 http://resolver.caltech.edu/CaltechAUTHORS:HUTprd05
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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.
|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.).|
|Subject Keywords:||dark energy; supernovae; equations of state; cosmology; red shift|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Lindsay Cleary|
|Deposited On:||26 Sep 2006|
|Last Modified:||26 Dec 2012 09:03|
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