KiDS+2dFLenS+GAMA: testing the cosmological model with the E-G statistic

Journal article

We present a new measurement of EG, which combines measurements of weak gravitational lensing, galaxy clustering, and redshift-space distortions. This statistic was proposed as a consistency test of General Relativity (GR) that is insensitive to linear, deterministic galaxy bias, and the matter clustering amplitude. We combine deep imaging data from KiDS with overlapping spectroscopy from 2dFLenS, BOSS DR12, and GAMA and find EG(z = 0.267) = 0.43 ± 0.13 (GAMA), EG(z = 0.305) = 0.27 ± 0.08 (LOWZ+2dFLOZ), and EG(z = 0.554) = 0.26 ± 0.07 (CMASS+2dFHIZ). We demonstrate that the existing tension in the value of thematter density parameter hinders the robustness of this statistic as solely a test of GR. We find that our EGmeasurements, as well as existing ones in the literature, favour a lower matter density cosmology than the cosmic microwave background. For a flat ΛCDM Universe, we find Ωm(z = 0) = 0.25 ± 0.03. With this paper, we publicly release the 2dFLenS data set at: http://2dflens.swin.edu.au.

Authors: Amon, A; Blake, C; Heymans, C; Leonard, C; Asgari, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 479
• Issue: 3
• Pages: 3422-3437
• Publication date: 2018-06-23
• Acceptance date: 2018-06-07
• DOI: 10.1093/mnras/sty1624
• EISSN: 1365-2966
• ISSN: 0035-8711
• Keywords: surveys, cosmology: observations, large-scale structure of Universe; gravitational lensing: weak