Dark Energy Survey Year 3 results: Constraints on extensions to ΛcDM with weak lensing and galaxy clustering
Desai, Shantanu (2023) Dark Energy Survey Year 3 results: Constraints on extensions to ΛcDM with weak lensing and galaxy clustering. Physical Review D, 107 (8). 083504. ISSN 24700010
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Abstract
We constrain six possible extensions to the Λ cold dark matter (CDM) model using measurements from the Dark Energy Survey's first three years of observations, alone and in combination with external cosmological probes. The DES data are the twopoint correlation functions of weak gravitational lensing, galaxy clustering, and their crosscorrelation. We use simulated data vectors and blind analyses of real data to validate the robustness of our results to astrophysical and modeling systematic errors. In many cases, constraining power is limited by the absence of theoretical predictions beyond the linear regime that are reliable at our required precision. The ΛCDM extensions are dark energy with a timedependent equation of state, nonzero spatial curvature, additional relativistic degrees of freedom, sterile neutrinos with eVscale mass, modifications of gravitational physics, and a binned σ8(z) model which serves as a phenomenological probe of structure growth. For the timevarying dark energy equation of state evaluated at the pivot redshift we find (wp,wa)=(0.990.17+0.28,0.9±1.2) at 68% confidence with zp=0.24 from the DES measurements alone, and (wp,wa)=(1.030.03+0.04,0.40.3+0.4) with zp=0.21 for the combination of all data considered. Curvature constraints of ωk=0.0009±0.0017 and effective relativistic species Neff=3.100.16+0.15 are dominated by external data, though adding DES information to external lowredshift probes tightens the ωk constraints that can be made without cosmic microwave background observables by 20%. For massive sterile neutrinos, DES combined with external data improves the upper bound on the mass meff by a factor of 3 compared to previous analyses, giving 95% limits of (ΔNeff,meff)≤(0.28,0.20 eV) when using priors matching a comparable Planck analysis. For modified gravity, we constrain changes to the lensing and Poisson equations controlled by functions ς(k,z)=ς0ωΛ(z)/ωΛ,0 and μ(k,z)=μ0ωΛ(z)/ωΛ,0, respectively, to ς0=0.60.5+0.4 from DES alone and (ς0,μ0)=(0.04±0.05,0.080.19+0.21) for the combination of all data, both at 68% confidence. Overall, we find no significant evidence for physics beyond ΛCDM.
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Item Type:  Article  
Uncontrolled Keywords:  Cold dark matter; Dark Energy Survey; Gravitational lensing; constraining power; timedependent equation; nonzero spatial curvature; degrees of freedom  
Subjects:  Physics Physics > Astronomy Astrophysics 

Divisions:  Department of Physics  
Depositing User:  Mr Nigam Prasad Bisoyi  
Date Deposited:  24 Sep 2023 09:27  
Last Modified:  24 Sep 2023 09:27  
URI:  http://raiith.iith.ac.in/id/eprint/11688  
Publisher URL:  https://doi.org/10.1103/PhysRevD.107.083504  
OA policy:  https://v2.sherpa.ac.uk/id/publication/32263  
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