Mancini, AS;
Köhlinger, F;
Joachimi, B;
Pettorino, V;
Schäfer, BM;
Reischke, R;
Uitert, EV;
... Lesgourgues, J; + view all
(2019)
KiDS+GAMA: Constraints on Horndeski gravity from combined large-scale structure probes.
Monthly Notices of the Royal Astronomical Society
, 490
(2)
pp. 2155-2177.
10.1093/mnras/stz2581.
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Abstract
We present constraints on Horndeski gravity from a combined analysis of cosmic shear, galaxy–galaxy lensing and galaxy clustering from 450deg2 of the Kilo-Degree Survey and the Galaxy And Mass Assembly survey.The Horndeski class of dark energy/modified gravity models includes the majority of universally coupled extensions to ΛCDM with one scalar field in addition to the metric. We study the functions of time that fully describe the evolution of linear perturbations in Horndeski gravity. Our results are compatible throughout with a ΛCDM model. By imposing gravitational wave constraints, we fix the tensor speed excess to zero and consider a subset of models including, e.g. quintessence and f(R) theories. Assuming proportionality of the Horndeski functions αB and αM (kinetic braiding and the Planck mass run rate, respectively) to the dark energy density fraction ΩDE(a) = 1 − Ωm(a), we find for the proportionality coefficients α^B=0.20+0.20−0.33 and α^M=0.25+0.19−0.29. Our value of S8≡σ8Ωm/0.3−−−−−−√ is in better agreement with the Planck estimate when measured in the enlarged Horndeski parameter space than in a pure ΛCDM scenario. In our joint three-probe analysis, we report a downward shift of the S8 best-fitting value from the Planck measurement of ΔS8=0.016+0.048−0.046 in Horndeski gravity, compared to ΔS8=0.059+0.040−0.039 in ΛCDM. Our constraints are robust to the modelling uncertainty of the non-linear matter power spectrum in Horndeski gravity. Our likelihood code for multiprobe analysis in both ΛCDM and Horndeski gravity is publicly available at https://github.com/alessiospuriomancini/KiDSHorndeski.
| Type: | Article |
|---|---|
| Title: | KiDS+GAMA: Constraints on Horndeski gravity from combined large-scale structure probes |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stz2581 |
| Publisher version: | http://dx.doi.org/10.1093/mnras/stz2581 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | gravitation, gravitational lensing: weak, methods: data analysis, methods: statistical, dark energy, large-scale structure of Universe |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10084343 |
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