期刊
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
卷 -, 期 3, 页码 -出版社
IOP Publishing Ltd
DOI: 10.1088/1475-7516/2019/03/043
关键词
cosmological parameters from LSS; physics of the early universe; stars
资金
- Spanish MINECO [AYA2014-58747-P]
- ICCUB (Unidad de Excelencia Maria de Maeztu) [MDM-2014-0369]
- European Union's Horizon 2020 research and innovation program ERC (BePreSySe) [725327]
- ASI [I/023/12/0, 2018-23-HH.0]
- grant PRIN MIUR 2015
- Labex Institut Lagrange de Paris (ILP) part of the Idex SUPER [ANR-10-LABX-63]
- Agence Nationale de la Recherche, as part of the programme Investissements d'avenir [ANR-11-IDEX-0004-02]
- Simons Foundation
- ANR BIG4 grant of the French Agence Nationale de la Recherche [ANR-16-CE23-0002]
The ages of the oldest stellar objects in our galaxy provide an independent test of the current cosmological model as they give a lower limit to the age of the Universe. Recent accurate parallaxes by the Gaia space mission, accurate measurements of the metallicity of stars, via individual elemental abundances, and advances in the modelling of stellar evolution, provide new, higher-precision age estimates of the oldest stellar populations in the galaxy: globular clusters and very-low-metallicity stars. The constraints on the age of the Universe, tu, so obtained are determined from the local Universe and at late time. It is well known that local and early-Universe determinations of another cosmological parameter closely related to the age of the Universe, the Hubble constant H-0, show a less than or similar to 3 sigma tension. In the standard cosmological model, ACDM, t(U) and H-0 are related by the matter density parameter Omega(m,0). We propose to combine local t(U) constraints with late-time Omega(m,0) estimates in a ACDM framework, to obtain a low-redshift H-0 determination that does not rely on early Universe physics. A proof-of-principle of this approach with current data gives H-0 = 71 +/- 2.8 (H-0 = 69.3 +/- 2.7) km s(-1) Mpc(-1) from globular clusters (very-low-metallicity stars) with excellent prospects for improved constraints in the near future.
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