DES Y1 results - K Romer.pdf (3.19 MB)
DES Y1 results: splitting growth and geometry to test ?cDM
journal contribution
posted on 2023-06-10, 00:47 authored by J Muir, E Baxter, V Miranda, C Doux, A Ferté, C D Leonard, D Huterer, B Jain, P Lemos, M Raveri, S Nadathur, A Campos, Sunayana Bhargava, Kathy RomerKathy Romer, Reese WilkinsonReese Wilkinson, DES Collaboration, othersWe analyze Dark Energy Survey (DES) data to constrain a cosmological model where a subset of parameters - focusing on ?m - are split into versions associated with structure growth (e.g., ?mgrow) and expansion history (e.g., ?mgeo). Once the parameters have been specified for the ?CDM 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-?CDM 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 ?mgrow=?mgeo. When DES and external data are analyzed separately, degeneracies with neutrino mass and intrinsic alignments limit our ability to measure ?mgrow, but combining DES with external data allows us to constrain both growth and geometric quantities. We also consider a parametrization where we split both ?m and w, but find that even our most constraining data combination is unable to separately constrain ?mgrow and wgrow. Relative to ?CDM, splitting growth and geometry weakens bounds on s8 but does not alter constraints on h.
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Publication status
- Published
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- Accepted version
Journal
Physical Review DISSN
2470-0010Publisher
American Physical SocietyExternal DOI
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2Volume
103Article number
a023528Department affiliated with
- Physics and Astronomy Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2021-08-31First Open Access (FOA) Date
2021-08-31First Compliant Deposit (FCD) Date
2021-08-27Usage metrics
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