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dc.contributor.authorLeaf, Kyle
dc.contributor.authorMelia, Fulvio
dc.date.accessioned2017-09-14T21:59:41Z
dc.date.available2017-09-14T21:59:41Z
dc.date.issued2017-09
dc.identifier.citationAnalysing H(z) data using two-point diagnostics 2017, 470 (2):2320 Monthly Notices of the Royal Astronomical Societyen
dc.identifier.issn0035-8711
dc.identifier.issn1365-2966
dc.identifier.doi10.1093/mnras/stx1437
dc.identifier.urihttp://hdl.handle.net/10150/625514
dc.description.abstractMeasurements of the Hubble constantH(z) are increasingly being used to test the expansion rate predicted by various cosmological models. But the recent application of two-point diagnostics, such as Om(zi, zj) and Omh(2)(zi, zj), has produced considerable tension between Lambda CDM's predictions and several observations, with other models faring even worse. Part of this problem is attributable to the continued mixing of truly model-independent measurements using the cosmic-chronometer approach, and model-dependent data extracted from baryon acoustic oscillations. In this paper, we advance the use of two-point diagnostics beyond their current status, and introduce new variations, which we call Delta h(zi, zj), that are more useful for model comparisons. But we restrict our analysis exclusively to cosmic-chronometer data, which are truly model independent. Even for these measurements, however, we confirm the conclusions drawn by earlier workers that the data have strongly non-Gaussian uncertainties, requiring the use of both 'median' and 'mean' statistical approaches. Our results reveal that previous analyses using two-point diagnostics greatly underestimated the errors, thereby misinterpreting the level of tension between theoretical predictions and H(z) data. Instead, we demonstrate that as of today, only Einstein-de Sitter is ruled out by the two-point diagnostics at a level of significance exceeding similar to 3s. The R-h = ct universe is slightly favoured over the remaining models, including Lambda cold dark matter and Chevalier-Polarski-Linder, though all of them (other than Einstein-de Sitter) are consistent to within 1 sigma with the measured mean of the Delta h(zi, zj) diagnostics.
dc.description.sponsorshipChinese Academy of Sciences Visiting Professorships for Senior International Scientists [2012T1J0011]; Chinese State Administration of Foreign Experts Affairs [GDJ20120491013]en
dc.language.isoenen
dc.publisherOXFORD UNIV PRESSen
dc.relation.urlhttps://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stx1437en
dc.rights© 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Societyen
dc.subjectgalaxies: distances and redshiftsen
dc.subjectgalaxies: evolutionen
dc.subjectlarge-scale structure of Universeen
dc.subjectcosmology: observationsen
dc.subjectcosmology: theoryen
dc.titleAnalysing H(z) data using two-point diagnosticsen
dc.typeArticleen
dc.contributor.departmentUniv Arizona, Dept Physen
dc.contributor.departmentUniv Arizona, Dept Phys, Program Appl Mathen
dc.contributor.departmentUniv Arizona, Dept Astronen
dc.identifier.journalMonthly Notices of the Royal Astronomical Societyen
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en
dc.eprint.versionFinal published versionen
refterms.dateFOA2018-09-11T22:46:36Z
html.description.abstractMeasurements of the Hubble constantH(z) are increasingly being used to test the expansion rate predicted by various cosmological models. But the recent application of two-point diagnostics, such as Om(zi, zj) and Omh(2)(zi, zj), has produced considerable tension between Lambda CDM's predictions and several observations, with other models faring even worse. Part of this problem is attributable to the continued mixing of truly model-independent measurements using the cosmic-chronometer approach, and model-dependent data extracted from baryon acoustic oscillations. In this paper, we advance the use of two-point diagnostics beyond their current status, and introduce new variations, which we call Delta h(zi, zj), that are more useful for model comparisons. But we restrict our analysis exclusively to cosmic-chronometer data, which are truly model independent. Even for these measurements, however, we confirm the conclusions drawn by earlier workers that the data have strongly non-Gaussian uncertainties, requiring the use of both 'median' and 'mean' statistical approaches. Our results reveal that previous analyses using two-point diagnostics greatly underestimated the errors, thereby misinterpreting the level of tension between theoretical predictions and H(z) data. Instead, we demonstrate that as of today, only Einstein-de Sitter is ruled out by the two-point diagnostics at a level of significance exceeding similar to 3s. The R-h = ct universe is slightly favoured over the remaining models, including Lambda cold dark matter and Chevalier-Polarski-Linder, though all of them (other than Einstein-de Sitter) are consistent to within 1 sigma with the measured mean of the Delta h(zi, zj) diagnostics.


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