ORCID Profile
0000-0003-1965-8614
Current Organisation
The University of Edinburgh
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Publisher: Oxford University Press (OUP)
Date: 19-02-2020
Abstract: Accurate modelling of non-linear scales in galaxy clustering will be crucial for data analysis of Stage IV galaxy surveys. A selection of competing non-linear models must be made based on validation studies. We provide a comprehensive set of forecasts of two different models for the halo redshift space power spectrum, namely the commonly applied TNS model and an effective field theory of large-scale structure (EFTofLSS) inspired model. Using simulation data and a least-χ2 analysis, we determine ranges of validity for the models. We then conduct an exploratory Fisher analysis using the full anisotropic power spectrum to investigate parameter degeneracies. We proceed to perform an MCMC analysis utilizing the monopole, quadrupole, and hexadecapole spectra, with a restricted range of scales for the latter in order to avoid biasing our growth rate, f, constraint. We find that the TNS model with a Lorentzian d ing and standard Eulerian perturbative modelling outperforms other variants of the TNS model. Our MCMC analysis finds that the EFTofLSS-based model may provide tighter marginalized constraints on f at z = 0.5 and z = 1 than the TNS model, despite having additional nuisance parameters. However this depends on the range of scales used as well as the fiducial values and priors on the EFT nuisance parameters. Finally, we extend previous work to provide a consistent comparison between the Fisher matrix and MCMC forecasts using the multipole expansion formalism, and find good agreement between them.
Publisher: EDP Sciences
Date: 05-2021
DOI: 10.1051/0004-6361/202039805
Abstract: We present constraints on extensions to the standard cosmological model of a spatially flat Universe governed by general relativity, a cosmological constant (Λ), and cold dark matter (CDM) by varying the spatial curvature Ω K , the sum of the neutrino masses ∑ m ν , the dark energy equation of state parameter w , and the Hu-Sawicki f ( R ) gravity f R 0 parameter. With the combined 3 × 2 pt measurements of cosmic shear from the Kilo-Degree Survey (KiDS-1000), galaxy clustering from the Baryon Oscillation Spectroscopic Survey (BOSS), and galaxy-galaxy lensing from the overlap between KiDS-1000, BOSS, and the spectroscopic 2-degree Field Lensing Survey, we find results that are fully consistent with a flat ΛCDM model with Ω K = 0.011 −0.057 +0.054 , ∑ m ν 1.76 eV (95% CL), and w = −0.99 −0.13 +0.11 . The f R 0 parameter is unconstrained in our fully non-linear f ( R ) cosmic shear analysis. Considering three different model selection criteria, we find no clear preference for either the fiducial flat ΛCDM model or any of the considered extensions. In addition to extensions to the flat ΛCDM parameter space, we also explore restrictions to common subsets of the flat ΛCDM parameter space by fixing the litude of the primordial power spectrum to the Planck best-fit value, as well as adding external data from supernovae and lensing of the cosmic microwave background (CMB). Neither the beyond-ΛCDM models nor the imposed restrictions explored in this analysis are able to resolve the ∼3 σ tension in S 8 between the 3 × 2 pt constraints and the Planck temperature and polarisation data, with the exception of w CDM, where the S 8 tension is resolved. The tension in the w CDM case persists, however, when considering the joint S 8 − w parameter space. The joint flat ΛCDM CMB lensing and 3 × 2 pt analysis is found to yield tight constraints on Ω m = 0.307 −0.013 +0.008 , σ 8 = 0.769 −0.010 +0.022 , and S 8 = 0.779 −0.013 +0.013 .
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Ben Bose.