Using Spatial Curvature with H II Galaxies and Cosmic Chronometers to Explore the Tension in H 0
AffiliationUniv Arizona, Dept Phys, Appl Math Program
Univ Arizona, Dept Astron
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PublisherIOP PUBLISHING LTD
CitationCheng-Zong Ruan et al 2019 ApJ 881 137
RightsCopyright © 2019. The American Astronomical Society.
Collection InformationThis 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 firstname.lastname@example.org.
AbstractWe present a model-independent measurement of spatial curvature Omega(k) in the Friedmann-Lemaitre-Robertson-Walker universe, based on observations of the Hubble parameter H(z) using cosmic chronometers, and a Gaussian process (GP) reconstruction of the H II galaxy Hubble diagram. We show that the imposition of spatial flatness (i.e., Omega(k) - 0) easily distinguishes between the Hubble constant measured with Planck and that based on the local distance ladder. We find an optimized curvature parameter Omega(k) = -0.120(-0.147)(+0.168) when using the former (i.e., H-0 = 67.66 +/- 0.42 km s(-1) Mpc(-1)), and Omega(k) = -0.298(-0.088)(+0.122) for the latter (H-0 = 73.24 +/- 1.74 km s(-1) Mpc(-1)). The quoted uncertainties are extracted by Monte Carlo sampling, taking into consideration the covariances between the function and its derivative reconstructed by GP. These data therefore reveal that the condition of spatial flatness favors the Planck measurement, while ruling out the locally inferred Hubble constant as a true measure of the large-scale cosmic expansion rate at a confidence level of similar to 3 sigma.
VersionFinal published version
SponsorsNational Key R&D Program of China [2017YFA0402600]; National Science Foundation of China [11573006, 11528306]; Fundamental Research Funds for the Central Universities; Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund