A 6% measurement of the Hubble parameter at z∼0.45: direct evidence of the epoch of cosmic re-acceleration

Deriving the expansion history of the Universe is a major goal of modern cosmology. To date, the most accurate measurements have been obtained with Type Ia Supernovae (SNe) and Baryon Acoustic Oscillations (BAO), providing evidence for the existence of a transition epoch at which the expansion rate changes from decelerated to accelerated. However, these results have been obtained within the framework of specific cosmological models that must be implicitly or explicitly assumed in the measurement. It is therefore crucial to obtain measurements of the accelerated expansion of the Universe independently of assumptions on cosmological models. Here we exploit the unprecedented statistics provided by the Baryon…

• NS
  National Science Foundation
• UD
  U.S. Department of Energy
• AP
  Alfred P. Sloan Foundation
• HU
  Harvard University
• JH
  Johns Hopkins University
• CM
  Carnegie Mellon University
• IC
  Imperial College London
• MD
  Ministero dell’Istruzione, dell’Università e della Ricerca

  Award: 2010-2011
• OO
  Office of Science
• CO
  College of Engineering, Michigan State University
• SA
  Science and Technology Facilities Council

  Awards: ST/N000668/1, ST/K00090X/1
• ID
  Institut de Ciències del Cosmos

  Award: MDM-2014-0369
• BN
  Brookhaven National Laboratory
• LB
  Lawrence Berkeley National Laboratory