The WiggleZ Dark Energy Survey: Measuring the cosmic expansion history using the Alcock-Paczynski test and distant supernovae

Chris Blake, Karl Glazebrook, Tamara Davis, Sarah Brough, Matthew Colless, Carlos Contreras, Warrick Couch, Scott Croom, Michael Drinkwater, Karl Forster, David Gilbank, Michael Gladders, Ben Jelliffe, Russell Jurek, I-hui Li, Barry Madore, Damien Martin, Kevin Pimbblet, Gregory Poole, Michael PracyRob Sharp, Emily Wisnioski, David Woods, Ted Wyder, Howard Yee

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    113 Citations (Scopus)


    Astronomical observations suggest that today s Universe is dominated by a dark energy of unknown physical origin. One of the most notable results obtained from many models is that dark energy should cause the expansion of the Universe to accelerate: but the expansion rate as a function of time has proved very difficult to measure directly. We present a new determination of the cosmic expansion history by combining distant supernovae observations with a geometrical analysis of large-scale galaxy clustering within the WiggleZ Dark Energy Survey, using the Alcock-Paczynski test to measure the distortion of standard spheres. Our result constitutes a robust and non-parametric measurement of the Hubble expansion rate as a function of time, which we measure with 10-15 per cent precision in four bins within the redshift range 0.1 <z <0.9. We demonstrate, in a manner insensitive to the assumed cosmological model, that the cosmic expansion is accelerating. Furthermore, we find that this expansion history is consistent with a cosmological-constant dark energy.
    Original languageEnglish
    Pages (from-to)1725 - 1735
    Number of pages11
    JournalMonthly Notices of the Royal Astronomical Society
    Issue number3
    Publication statusPublished - 2011

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