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

Abstract

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 analyze different combinations of the observables, finding that galaxy-galaxy lensing measurements are particularly useful in improving the constraint on the intrinsic alignment amplitude (by 30%, positive at 3.5σ in the fiducial data analysis), while the multipole power spectra are useful in tightening the constraints along the lensing degeneracy direction (e.g. factor of two improvement in the matter density constraint in the fiducial analysis). The fully combined constraint on S 8 ≡ σ 8 Ω m /0.3 = 0.742 ± 0.035, which is an improvement by 20% compared to KiDS alone, corresponds to a 2.6σ 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 favored in a model selection sense, including the sum of neutrino masses, curvature, evolving dark energy (both constant and time-varying equations of state), 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. We make our measurements and fitting pipeline public at https://github.com/sjoudaki/CosmoLSS.

Spherically symmetric black holes with electric and magnetic charge in extended gravity: physical properties, causal structure, and stability analysis in Einstein’s and Jordan’s frames

“…In the usual black hole, the lensing effects occur only in the region near the black hole but for the geometry expressed by the metric (13) the effects occur in a rather large region, say interstellar region, around the black hole. Therefore the big ring much greater than the standard Einstein ring or double images separated in a large angle could be observed as in the observation of the standard weak lensing as in [89][90][91] in future.…”

Dark Energy Survey Year 1 results: Cosmological constraints from cosmic shear

“…For recent real-space cosmic shear data, including DES SV [33] and KiDS-450 [35], we use the original ξ AE , n i ðzÞ, covariance matrix, and priors on shear or photo-z systematics from these works that inform limitations to the data sets. We have not corrected a bug in the published angular values θ in the original KiDS-450 measurements that was reported in Footnote 1 of [39], instead using the published Table III. Especially for external data, it is important to remember that we vary Ω ν h 2 in our fiducial analysis, and thus all results we compare to, and so the central values and uncertainties of parameters may not follow intuition from previous results.…”

“…Cosmic shear from 139 deg 2 of the DES Science Verification (SV) data was used to place the first constraint on cosmology with DES [33] using both real-and harmonic-space measurements. Cosmic shear has also recently been measured using KiDS data [34,35], which was used in [35][36][37][38][39] to place tomographic constraints on cosmology.…”

Tension of the EG statistic and redshift space distortion data with the Planck - ΛCDM model and implications for weakening gravity

“…Modified gravity (MG) models constitute a prime theoretical candidate to explain this tension. The combination of cosmological observational probes is a powerful tool for the identification of signatures of MG [19][20][21][22][23][24][25]. Such observational probes may be divided in two classes: geometric and dynamical (or structure formation) probes [26][27][28][29].…”