Monday, December 17, 2012

1212.3339 (Fergus Simpson et al.)

CFHTLenS: Testing the Laws of Gravity with Tomographic Weak Lensing and Redshift Space Distortions    [PDF]

Fergus Simpson, Catherine Heymans, David Parkinson, Chris Blake, Martin Kilbinger, Jonathan Benjamin, Thomas Erben, Hendrik Hildebrandt, Henk Hoekstra, Thomas D. Kitching, Yannick Mellier, Lance Miller, Ludovic Van Waerbeke, Jean Coupon, Liping Fu, Joachim Harnois-Déraps, Michael J. Hudson, Konrad Kuijken, Barnaby Rowe, Tim Schrabback, Elisabetta Semboloni, Sanaz Vafaei, Malin Velander
Dark energy may be the first sign of new fundamental physics in the Universe, taking either a physical form or revealing a correction to Einsteinian gravity. Weak gravitational lensing and galaxy peculiar velocities provide complementary probes of General Relativity, and in combination allow us to test modified theories of gravity in a unique way. We perform such an analysis by combining measurements of cosmic shear tomography from the Canada-France Hawaii Telescope Lensing Survey (CFHTLenS) with the growth of structure from the WiggleZ Dark Energy Survey and the Six-degree-Field Galaxy Survey (6dFGS), producing the strongest existing joint constraints on the metric potentials that describe general theories of gravity. For scale-independent modifications to the metric potentials which evolve linearly with the effective dark energy density, we find present-day cosmological deviations in the Newtonian potential and curvature potential from the prediction of General Relativity to be (Delta Psi)/Psi = 0.05 \pm 0.25 and (Delta Phi)/Phi = -0.05 \pm 0.3 respectively (68 per cent CL).
View original: http://arxiv.org/abs/1212.3339

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