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Title: Dark Energy Survey Year 1 Results: Constraints on Extended Cosmological Models from Galaxy Clustering and Weak Lensing

Abstract

We present constraints on extensions of the minimal cosmological models dominated by dark matter and dark energy, $$\Lambda$$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 $$\Omega_k$$, 2) number of relativistic species $$N_{\rm eff}$$ 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 $$\mu_0$$ and $$\Sigma_0$$ that modify the metric potentials. We also consider external information from Planck CMB measurements; BAO measurements from SDSS, 6dF, and BOSS; RSD measurements from BOSS; and SNIa information from the Pantheon compilation. Constraints on curvature and the number of relativistic species are dominated by the external data; when these are combined with DES Y1, we find $$\Omega_k=0.0020^{+0.0037}_{-0.0032}$$ at the 68\% confidence level, and $$N_{\rm eff}<3.28\, (3.55)$$ at 68\% (95\%) confidence. For the time-varying equation-of-state, we find the pivot value $$(w_p, w_a)=(-0.91^{+0.19}_{-0.23}, -0.57^{+0.93}_{-1.11})$$ at pivot redshift $$z_p=0.27$$ from DES alone, and $$(w_p, w_a)=(-1.01^{+0.04}_{-0.04}, -0.28^{+0.37}_{-0.48})$$ 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 $$\Sigma_0= 0.43^{+0.28}_{-0.29}$$ from DES Y1 alone, and $$(\Sigma_0, \mu_0)=(0.06^{+0.08}_{-0.07}, -0.11^{+0.42}_{-0.46})$$ from DES Y1 combined with external data, consistent with predictions from GR.

Authors:
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Org.:
DES
OSTI Identifier:
1487047
Report Number(s):
arXiv:1810.02499; FERMILAB-PUB-18-507-PPD
1697159
DOE Contract Number:  
AC02-07CH11359
Resource Type:
Journal Article
Journal Name:
TBD
Additional Journal Information:
Journal Name: TBD
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Abbott, T. M.C., and et al. Dark Energy Survey Year 1 Results: Constraints on Extended Cosmological Models from Galaxy Clustering and Weak Lensing. United States: N. p., 2018. Web.
Abbott, T. M.C., & et al. Dark Energy Survey Year 1 Results: Constraints on Extended Cosmological Models from Galaxy Clustering and Weak Lensing. United States.
Abbott, T. M.C., and et al. Thu . "Dark Energy Survey Year 1 Results: Constraints on Extended Cosmological Models from Galaxy Clustering and Weak Lensing". United States. https://www.osti.gov/servlets/purl/1487047.
@article{osti_1487047,
title = {Dark Energy Survey Year 1 Results: Constraints on Extended Cosmological Models from Galaxy Clustering and Weak Lensing},
author = {Abbott, T. M.C. and et al.},
abstractNote = {We present constraints on extensions of the minimal cosmological models dominated by dark matter and dark energy, $\Lambda$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 $\Omega_k$, 2) number of relativistic species $N_{\rm eff}$ 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 $\mu_0$ and $\Sigma_0$ that modify the metric potentials. We also consider external information from Planck CMB measurements; BAO measurements from SDSS, 6dF, and BOSS; RSD measurements from BOSS; and SNIa information from the Pantheon compilation. Constraints on curvature and the number of relativistic species are dominated by the external data; when these are combined with DES Y1, we find $\Omega_k=0.0020^{+0.0037}_{-0.0032}$ at the 68\% confidence level, and $N_{\rm eff}<3.28\, (3.55)$ at 68\% (95\%) confidence. For the time-varying equation-of-state, we find the pivot value $(w_p, w_a)=(-0.91^{+0.19}_{-0.23}, -0.57^{+0.93}_{-1.11})$ at pivot redshift $z_p=0.27$ from DES alone, and $(w_p, w_a)=(-1.01^{+0.04}_{-0.04}, -0.28^{+0.37}_{-0.48})$ 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 $\Sigma_0= 0.43^{+0.28}_{-0.29}$ from DES Y1 alone, and $(\Sigma_0, \mu_0)=(0.06^{+0.08}_{-0.07}, -0.11^{+0.42}_{-0.46})$ from DES Y1 combined with external data, consistent with predictions from GR.},
doi = {},
journal = {TBD},
number = ,
volume = ,
place = {United States},
year = {2018},
month = {10}
}

Journal Article:

Figures / Tables:

Table I Table I: Summary of the extensions to the ΛCDM model that we study in this paper, the parameters that describe these extensions, and the (flat) priors given to these parameters. In addition to the priors listed in the table, we also impose the prior w0 + wa ≤ 0 formore » dark energy, and 2Σ0 + 1 > µ0 for modified gravity.« less

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Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.