Abbott, TMC;
Abdalla, FB;
Avila, S;
Banerji, M;
Baxter, E;
Bechtol, K;
Becker, MR;
... Zuntz, J; + view all
(2019)
Dark Energy Survey year 1 results: Constraints on extended cosmological models from galaxy clustering and weak lensing.
Physical Review D
, 99
(12)
, Article 123505. 10.1103/PhysRevD.99.123505.
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Abstract
We present constraints on extensions of the minimal cosmological models dominated by dark matter and dark energy, Λ CDM and w CDM , by using a combined analysis of galaxy clustering and weak gravitational lensing from the first-year data of the Dark Energy Survey (DES Y1) in combination with external data. We consider four extensions of the minimal dark energy-dominated scenarios: (1) nonzero curvature Ω k , (2) number of relativistic species N eff different from the standard value of 3.046, (3) time-varying equation-of-state of dark energy described by the parameters w 0 and w a (alternatively quoted by the values at the pivot redshift, w p , and w a ), and (4) modified gravity described by the parameters μ 0 and Σ 0 that modify the metric potentials. We also consider external information from Planck cosmic microwave background measurements; baryon acoustic oscillation measurements from SDSS, 6dF, and BOSS; redshift-space distortion measurements from BOSS; and type Ia supernova information from the Pantheon compilation of datasets. Constraints on curvature and the number of relativistic species are dominated by the external data; when these are combined with DES Y1, we find Ω k = 0.002 0 + 0.0037 − 0.0032 at the 68% confidence level, and the upper limit N eff < 3.28 ( 3.55 ) at 68% (95%) confidence, assuming a hard prior N eff > 3.0 . For the time-varying equation-of-state, we find the pivot value ( w p , w a ) = ( − 0.9 1 + 0.19 − 0.23 , − 0.5 7 + 0.93 − 1.11 ) at pivot redshift z p = 0.27 from DES alone, and ( w p , w a ) = ( − 1.0 1 + 0.04 − 0.04 , − 0.2 8 + 0.37 − 0.48 ) at z p = 0.20 from DES Y1 combined with external data; in either case we find no evidence for the temporal variation of the equation of state. For modified gravity, we find the present-day value of the relevant parameters to be Σ 0 = 0.4 3 + 0.28 − 0.29 from DES Y1 alone, and ( Σ 0 , μ 0 ) = ( 0.0 6 + 0.08 − 0.07 , − 0.1 1 + 0.42 − 0.46 ) from DES Y1 combined with external data. These modified-gravity constraints are consistent with predictions from general relativity.
| Type: | Article |
|---|---|
| Title: | Dark Energy Survey year 1 results: Constraints on extended cosmological models from galaxy clustering and weak lensing |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1103/PhysRevD.99.123505 |
| Publisher version: | https://doi.org/10.1103/PhysRevD.99.123505 |
| 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. |
| 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 |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10076652 |
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