KiDS-450 + 2dFLenS: Cosmological parameter constraints from weak gravitational lensing tomography and overlapping redshift-space galaxy clustering

By S. Joudaki, C. Blake, Andrew Johnson, A. Amon, M. Asgari, A. Choi, T. Erben, Karl Glazebrook, J. Harnois-Déraps, Catherine Heymans and 12 more. 2017

230 citations recorded by the source corpus.

We perform a combined analysis of cosmic shear tomography, galaxy-galaxy lensing tomography, and redshift-space multipole power spectra (monopole and quadrupole) using 450 deg(2) of imaging data by the Kilo Degree Survey (KiDS-450) overlapping with two spectroscopic surveys: the 2-degree Field Lensing Survey (2dFLenS) and the Baryon Oscillation Spectroscopic Survey (BOSS). We restrict the galaxy-galaxy lensing and multipole power spectrum measurements to the overlapping regions with KiDS, and self-consistently compute the full covariance between the different observables using a large suite of N-body simulations. We methodically analyse different combinations of the observables, finding that the galaxy-galaxy lensing measurements are particularly useful in improving the constraint on the intrinsic alignment amplitude, while the multipole power spectra are useful in tightening the constraints along the lensing degeneracy direction. The fully combined constraint on S-8 = sigma(8) root Omega(m)/0.3 = 0.742 +/- 0.035, which is an improvement by 20 per cent compared to KiDS alone, corresponds to a 2.6 sigma discordance with Planck, and is not significantly affected by fitting to a more conservative set of scales. Given the tightening of the parameter space, we are unable to resolve the discordance with an extended cosmology that is simultaneously favoured in a model selection sense, including the sum of neutrino masses, curvature, evolving dark energy and modified gravity. The complementarity of our observables allows for constraints on modified gravity degrees of freedom that are not simultaneously bounded with either probe alone, and up to a factor of three improvement in the S-8 constraint in the extended cosmology compared to KiDS alone.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/e50c1f020a0c9dc5d9b5828ab8211c1d04cf1657

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Citations in the corpus

A unified pseudo-Cℓ framework (2018, methodology): “These measurements will mostly follow a tomographic approach, using the angular auto- and cross-power spectra between these observables across different bins of photometric redshift (Krause et al. 2017; Joudaki et al. 2018; DES Collaboration et al. 2017).”
Possible signals of vacuum dynamics in the Universe (2017, methodology): “Let us note that an account of the LSS observations does not only concern the f(z)σ8(z) data, but also the weak gravitational lensing constraints existing in the literature on the conventional quantity S8 ≡ σ8(Ωm/0.3)0.5 (Joudaki et al. 2018; Hildebrandt et al. 2017; Heymans et al. 2013).”
KiDS+GAMA : cosmology constraints from a joint analysis of cosmic shear, galaxy-galaxy lensing, and angular clustering (2017, methodology): “We fitted cosmological models to our data using the updated version of the COSMOMC pipeline from Joudaki et al. (2017a), extended to simultaneously model galaxy–galaxy lensing measurements (Joudaki et al. 2018).”
Evolution of the f σ 8 tension with the Planck 15 / Λ CDM determination and implications for modified gravity theories (2018, background): “KiDS [22, 117] or the DES data [25, 118–120]) and the Planck Sunyaev-Zeldovich (SZ) cluster counts [121].”
CMB-S4 Science Case, Reference Design, and Project Plan (2019, background): “These possibilities may also play a role in explaining the discrepancies observed in the Hubble constant H0 measurements [160, 161, 162, 163, 164], the amplitude of fluctuations σ8 [165, 166, 167, 168], and clustering on small scales [169, 127].”
KiDS+VIKING-450: Cosmic shear tomography with optical and infrared data (2018, methodology): “Joudaki et al. (2018) and Troxel et al. (2018a) discuss using the average weighted pair separation instead of the logarithmic midpoint (as it was done in H17) of the bin to calculate the model.”
Interacting dark energy in the early 2020s: A promising solution to the H0 and cosmic shear tensions (2019, methodology): “radiation, but a number of more complex scenarios have been studied, e.g. [10{109]. On the other hand, tensions between cosmic shear surveys (such as [110{112]) and CMB measurements have also emerged [111, 113, 114]. For instance, the quantity S 8 ˙ 8( m=0:3)0:5 as measured by the KiDS weak lensing ”
Cosmology from the Chinese Space Station Optical Survey (CSS-OS) (2019, background): “For simplicity, we fix βIA = 0 here, i.e. we do not consider luminosity dependence, since the change of the average luminosity can be ignored across different tomographic bins (Hildebrandt et al. 2016; Joudaki et al. 2017).”
KiDS+VIKING-450 and DES-Y1 combined: Cosmology with cosmic shear (2019, methodology): “The cosmological constraints on KV450 and DES-Y1 are obtained using the CosmoLSS3 likelihood code (Joudaki et al. 2018) in a Markov Chain Monte Carlo (MCMC) analysis.”