KiDS-450: testing extensions to the standard cosmological model

By S. Joudaki, A. Mead, C. Blake, A. Choi, J. D. de Jong, T. Erben, I. F. Conti, R. Herbonnet, Catherine Heymans, H. Hildebrandt and 9 more. 2016

170 citations recorded by the source corpus.

We test extensions to the standard cosmological model with weak gravitational lensing tomography using 450 deg$^2$ of imaging data from the Kilo Degree Survey (KiDS). In these extended cosmologies, which include massive neutrinos, nonzero curvature, evolving dark energy, modified gravity, and running of the scalar spectral index, we also examine the discordance between KiDS and cosmic microwave background measurements from Planck. The discordance between the two datasets is largely unaffected by a more conservative treatment of the lensing systematics and the removal of angular scales most sensitive to nonlinear physics. The only extended cosmology that simultaneously alleviates the discordance with Planck and is at least moderately favored by the data includes evolving dark energy with a time-dependent equation of state (in the form of the $w_0-w_a$ parameterization). In this model, the respective $S_8 = \sigma_8 \sqrt{\Omega_{\rm m}/0.3}$ constraints agree at the $1\sigma$ level, and there is `substantial concordance' between the KiDS and Planck datasets when accounting for the full parameter space. Moreover, the Planck constraint on the Hubble constant is wider than in LCDM and in agreement with the Riess et al. (2016) direct measurement of $H_0$. The dark energy model is moderately favored as compared to LCDM when combining the KiDS and Planck measurements, and remains moderately favored after including an informative prior on the Hubble constant. In both of these scenarios, the dark energy parameters are discrepant with a cosmological constant at the $3\sigma$ level. Moreover, KiDS constrains the sum of neutrino masses to 4.0 eV (95% CL), finds no preference for time or scale dependent modifications to the metric potentials, and is consistent with flatness and no running of the spectral index. The analysis code is publicly available at https://github.com/sjoudaki/kids450

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/e99e2720537ed0a725d091c35beb4311133ff066

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Citations in the corpus

Quantifying baryon effects on the matter power spectrum and the weak lensing shear correlation (2018, result): “This conclusion is in agreement with other findings on the importance of baryon effects from KiDS [67, 70] and the HSC survey [71].”
Cosmology from cosmic shear power spectra with Subaru Hyper Suprime-Cam first-year data (2018, methodology): “…from the KiDS-450 correlation function analysis (Hildebrandt et al. 2017), 0.651± 0.058 from the KiDS-450 power spectrum analysis (Köhlinger et al. 2017), 0.732+0.029−0.031 from CFHTLenS (Joudaki et al. 2017), and 0.782+0.027−0.027 from DES year one (Y1) data (Troxel et al. 2017).”
Galileon gravity in light of ISW, CMB, BAO and H0 data (2017, background): “[111] for an investigation of the impact of departures from ΛCDM in alleviating the tension that currently exists between these two datasets).”
KiDS-450: The tomographic weak lensing power spectrum and constraints on cosmological parameters (2017, methodology): “We do not include a redshift or luminosity dependence in the IA modelling as those were found to be negligible by Joudaki et al. (2017).”
KiDS+GAMA : cosmology constraints from a joint analysis of cosmic shear, galaxy-galaxy lensing, and angular clustering (2017, methodology): “This includes the results from Joudaki et al. (2017a), who re-analysed the shear correlation functions from CFHTLenS (Heymans et al. 2013) using the extended version of COSMOMC that we used here as well.”
KiDS-450 + 2dFLenS: Cosmological parameter constraints from weak gravitational lensing tomography and overlapping redshift-space galaxy clustering (2017, methodology): “…we have developed a self-consistent Markov Chain Monte Carlo (MCMC) fitting pipeline in COSMOMC (Lewis & Bridle 2002), which is an extension of the pipeline used in the cosmic shear analyses of CFHTLenS (Joudaki et al. 2017a) and KiDS-450 (Hildebrandt et al. 2017; Joudaki et al. 2017b).”
KiDS+VIKING-450: Cosmic shear tomography with optical and infrared data (2018, methodology): “This episode illustrates that our analysis was never blind against the values of Ωm and σ8, whose values are also affected by our prior choices (for a detailed discussion of this effect see Joudaki et al. 2017a).”
Cosmology Intertwined II: The Hubble Constant Tension (2020, unknown): “[78] S.”