DES Y1 results: Splitting growth and geometry to test ΛcDM

Muir, J. and Baxter, E. and Miranda, V. and Desai, Shantanu et. al. (2021) DES Y1 results: Splitting growth and geometry to test ΛcDM. Physical Review D, 103 (023528). ISSN 2470-0010

[img] Text

Download (3MB)


We analyze Dark Energy Survey (DES) data to constrain a cosmological model where a subset of parameters - focusing on ωm - are split into versions associated with structure growth (e.g., ωmgrow) and expansion history (e.g., ωmgeo). Once the parameters have been specified for the ΛCDM cosmological model, which includes general relativity as a theory of gravity, it uniquely predicts the evolution of both geometry (distances) and the growth of structure over cosmic time. Any inconsistency between measurements of geometry and growth could therefore indicate a breakdown of that model. Our growth-geometry split approach therefore serves both as a (largely) model-independent test for beyond-ΛCDM physics, and as a means to characterize how DES observables provide cosmological information. We analyze the same multiprobe DES data as [Phys. Rev. Lett. 122, 171301 (2019)PRLTAO0031-900710.1103/PhysRevLett.122.171301]: DES Year 1 (Y1) galaxy clustering and weak lensing, which are sensitive to both growth and geometry, as well as Y1 BAO and Y3 supernovae, which probe geometry. We additionally include external geometric information from BOSS DR12 BAO and a compressed Planck 2015 likelihood, and external growth information from BOSS DR12 RSD. We find no significant disagreement with ωmgrow=ωmgeo. When DES and external data are analyzed separately, degeneracies with neutrino mass and intrinsic alignments limit our ability to measure ωmgrow, but combining DES with external data allows us to constrain both growth and geometric quantities. We also consider a parametrization where we split both ωm and w, but find that even our most constraining data combination is unable to separately constrain ωmgrow and wgrow. Relative to ΛCDM, splitting growth and geometry weakens bounds on σ8 but does not alter constraints on h.

[error in script]
IITH Creators:
IITH CreatorsORCiD
Desai, Shantanu
Item Type: Article
Uncontrolled Keywords: Galaxies, Gravitational Lensing, Dark Energy
Subjects: Physics
Physics > Classical mechanics
Physics > Fluid mechanics
Physics > Electricity and electronics
Physics > Astronomy Astrophysics
Divisions: Department of Physics
Depositing User: . LibTrainee 2021
Date Deposited: 31 May 2021 04:45
Last Modified: 31 Aug 2021 07:16
Publisher URL:
OA policy:
Related URLs:

Actions (login required)

View Item View Item
Statistics for RAIITH ePrint 7867 Statistics for this ePrint Item