Journal Article

An original constraint on the Hubble constant: <i>h</i> > 0.74

A. Barrau, A. Gorecki and J. Grain

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 389, issue 2, pages 919-924
Published in print September 2008 | ISSN: 0035-8711
Published online September 2008 | e-ISSN: 1365-2966 | DOI:
An original constraint on the Hubble constant: h > 0.74

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The Hubble parameter H0 is still not very well measured. Although the Hubble Key Project, Chandra and the Wilkinson Microwave Anisotropy Probe gave good estimates, the uncertainties remain quite large. In this brief report, we suggest an original and independent method to derive a lower limit on H0 using the absorption of very high energy γ-rays by the cosmic infrared background. With conservative hypotheses, we obtain H0 > 74 km s−1Mpc−1 at the 68 per cent confidence level, which favours the upper end of the intervals allowed by dedicated experiments.

Keywords: cosmological parameters; diffuse radiation

Journal Article.  5018 words.  Illustrated.

Subjects: Astronomy and Astrophysics

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