The VIMOS Public Extragalactic Redshift Survey (VIPERS): Gravity test from the combination of redshift-space distortions and galaxy-galaxy lensing at 0.5 < z < 1.2

Full list of authors: De La Torre, S.; Jullo, E.; Giocoli, C.; Pezzotta, A.; Bel, J.; Granett, B. R.; Guzzo, L.; Garilli, B.; Scodeggio, M.; Bolzonella, M.; Abbas, U.; Adami, C.; Bottini, D.; Cappi, A.; Cucciati, O.; Davidzon, I.; Franzetti, P.; Fritz, A.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Malek, K.; Marulli, F.; Polletta, M.; Pollo, A.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Arnouts, S.; Branchini, E.; Coupon, J.; De Lucia, G.; Ilbert, O.; Moutard, T.; Moscardini, L.; Peacock, J. A.; Metcalf, R. B.; Prada, F.; Yepes, G.
We carry out a joint analysis of redshift-space distortions and galaxy-galaxy lensing, with the aim of measuring the growth rate of structure; this is a key quantity for understanding the nature of gravity on cosmological scales and late-Time cosmic acceleration. We make use of the final VIPERS redshift survey dataset, which maps a portion of the Universe at a redshift of z 0.8, and the lensing data from the CFHTLenS survey over the same area of the sky. We build a consistent theoretical model that combines non-linear galaxy biasing and redshift-space distortion models, and confront it with observations. The two probes are combined in a Bayesian maximum likelihood analysis to determine the growth rate of structure at two redshifts z = 0.6 and z = 0.86. We obtain measurements of fσ(0.6) = 0.48 ± 0.12 and fσ(0.86) = 0.48 ± 0.10. The additional galaxy-galaxy lensing constraint alleviates galaxy bias and σ degeneracies, providing direct measurements of f and σ: [f(0.6),σ(0.6)] = [0.93 ± 0.22,0.52 ± 0.06] and [f(0.86),σ(0.86)] = [0.99 ± 0.19,0.48 ± 0.04]. These measurements are statistically consistent with a Universe where the gravitational interactions can be described by General Relativity, although they are not yet accurate enough to rule out some commonly considered alternatives. Finally, as a complementary test we measure the gravitational slip parameter, E, for the first time at z > 0.6. We find values of E (0.6) = 0.16±0.09 and E (0.86) = 0.09±0.07, when E is averaged over scales above 3 h Mpc. We find that our E measurements exhibit slightly lower values than expected for standard relativistic gravity in a ΛCDM background, although the results are consistent within 1-2σ. © ESO, 2017.
We acknowledge the crucial contribution of the ESO staff for the management of service observations. Italian participation to VIPERS has been funded by INAF through PRIN 2008, 2010, 2014 and 2015 programs. L.G. and B.R.G. acknowledge support from the European Research Council through grant No. 291521. O.L.F. acknowledges support from the European Research Council through grant No. 268107. J.A.P. acknowledges support of the European Research Council through the COSFORM ERC Advanced Research Grant (#670193). G.D.L. acknowledges financial support from the European Research Council through grant No. 202781. R.T. acknowledges financial support from the European Research Council through grant No. 202686. A.P., K.M., and J.K. have been supported by the National Science Centre (grants UMO-2012/07/B/ST9/04425 and UMO-2013/09/D/ST9/04030). E.B., F.M., and L.M. acknowledge the support from grants ASI-INAF I/023/12/0 and PRIN MIUR 2010-2011. L.M. also acknowledges financial support from PRIN INAF 2012. S.D.L.T., E.J., and M.P. acknowledge the support of the OCEVU Labex (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02) funded by the "Investissements d'Avenir" French government program managed by the ANR. Research conducted within the scope of the HECOLS International Associated Laboratory, supported in part by the Polish NCN grant Dec-2013/08/M/ST9/00664. T.M. and S.A. acknowledge financial support from the ANR Spin(e) through the French grant ANR-13-BS05-0005. The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) and the Partnership for Advanced Supercomputing in Europe (PRACE, www.prace-ri.eu) for funding the MultiDark simulation project by providing computing time on the GCS Supercomputer SuperMUC at Leibniz Supercomputing Centre (LRZ,www.lrz.de).