scholarly journals The Gravitational Lensing in Redshift-Space Correlation Functions of Galaxies and Quasars

2000 ◽  
Vol 537 (2) ◽  
pp. L77-L80 ◽  
Author(s):  
Takahiko Matsubara
Keyword(s):  
Gravitational Lensing ◽  
Correlation Functions ◽  
Space Correlation

The Real Space and Redshift Space Correlation Functions at Redshiftz= 1/3

1997 ◽  
Vol 479 (1) ◽  
pp. 82-89 ◽  
Author(s):  
C. W. Shepherd ◽  
R. G. Carlberg ◽  
H. K. C. Yee ◽  
E. Ellingson
Keyword(s):  
Correlation Functions ◽  
Real Space ◽  
Space Correlation ◽  
The Real

scholarly journals Cosmological lensing ratios with DES Y1, SPT, and Planck

2019 ◽  
Vol 487 (1) ◽  
pp. 1363-1379 ◽  
Author(s):  
J Prat ◽  
E Baxter ◽  
T Shin ◽  
C Sánchez ◽  
C Chang ◽  
...  
Keyword(s):  
Gravitational Lensing ◽  
Correlation Functions ◽  
Signal To Noise Ratio ◽  
Cosmic Time ◽  
Cosmological Constraints ◽  
Photometric Redshift ◽  
Dark Energy Survey ◽  
Systematic Uncertainties ◽  
South Pole Telescope ◽  
Curvature Parameter

ABSTRACTCorrelations between tracers of the matter density field and gravitational lensing are sensitive to the evolution of the matter power spectrum and the expansion rate across cosmic time. Appropriately defined ratios of such correlation functions, on the other hand, depend only on the angular diameter distances to the tracer objects and to the gravitational lensing source planes. Because of their simple cosmological dependence, such ratios can exploit available signal-to-noise ratio down to small angular scales, even where directly modelling the correlation functions is difficult. We present a measurement of lensing ratios using galaxy position and lensing data from the Dark Energy Survey, and CMB lensing data from the South Pole Telescope and Planck, obtaining the highest precision lensing ratio measurements to date. Relative to the concordance ΛCDM model, we find a best-fitting lensing ratio amplitude of A = 1.1 ± 0.1. We use the ratio measurements to generate cosmological constraints, focusing on the curvature parameter. We demonstrate that photometrically selected galaxies can be used to measure lensing ratios, and argue that future lensing ratio measurements with data from a combination of LSST and Stage-4 CMB experiments can be used to place interesting cosmological constraints, even after considering the systematic uncertainties associated with photometric redshift and galaxy shear estimation.

scholarly journals Statistical separation of weak gravitational lensing and intrinsic ellipticities based on galaxy colour information

2020 ◽  
Vol 494 (2) ◽  
pp. 2969-2981 ◽  
Author(s):  
Tim M Tugendhat ◽  
Robert Reischke ◽  
Björn Malte Schäfer
Keyword(s):  
Parameter Estimation ◽  
Gravitational Lensing ◽  
Correlation Functions ◽  
Weak Lensing ◽  
Model Parameters ◽  
Linear Combinations ◽  
Statistical Separation ◽  
Cent Level ◽  
Model Independent ◽  
Alignment Model

ABSTRACT Intrinsic alignments of galaxies are recognized as one of the most important systematic in weak lensing surveys on small angular scales. In this paper, we investigate ellipticity correlation functions that are measured separately on elliptical and spiral galaxies, for which we assume the generic alignment mechanisms based on tidal shearing and tidal torquing, respectively. Including morphological information allows to find linear combinations of measured ellipticity correlation functions that suppress the gravitational lensing signal completely or which show a strongly boosted gravitational lensing signal relative to intrinsic alignments. Specifically, we find that (i) intrinsic alignment spectra can be measured in a model-independent way at a significance of Σ ≃ 60 with a wide-angle tomographic survey such as Euclid’s, (ii) the underlying intrinsic alignment model parameters can be determined at per cent-level precision, (iii) this measurement is not impeded by misclassifying galaxies and assuming a wrong alignment model, (iv) parameter estimation from a cleaned weak lensing spectrum is possible with almost no bias, and (v) the misclassification would not strongly impact parameter estimation from the boosted weak lensing spectrum.

scholarly journals Cosmological constraints from cosmic shear two-point correlation functions with HSC survey first-year data

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Takashi Hamana ◽  
Masato Shirasaki ◽  
Satoshi Miyazaki ◽  
Chiaki Hikage ◽  
Masamune Oguri ◽  
...  
Keyword(s):  
Gravitational Lensing ◽  
Correlation Functions ◽  
Cold Dark Matter ◽  
First Year ◽  
Model Errors ◽  
Redshift Distribution ◽  
Cosmological Constraints ◽  
Modeling Uncertainties ◽  
Point Correlation ◽  
Cosmic Shear

Abstract We present measurements of cosmic shear two-point correlation functions (TPCFs) from Hyper Suprime-Cam Subaru Strategic Program (HSC) first-year data, and derive cosmological constraints based on a blind analysis. The HSC first-year shape catalog is divided into four tomographic redshift bins ranging from $z=0.3$ to 1.5 with equal widths of $\Delta z =0.3$. The unweighted galaxy number densities in each tomographic bin are 5.9, 5.9, 4.3, and $2.4\:$arcmin$^{-2}$ from the lowest to highest redshifts, respectively. We adopt the standard TPCF estimators, $\xi _\pm$, for our cosmological analysis, given that we find no evidence of significant B-mode shear. The TPCFs are detected at high significance for all 10 combinations of auto- and cross-tomographic bins over a wide angular range, yielding a total signal-to-noise ratio of 19 in the angular ranges adopted in the cosmological analysis, $7^{\prime }<\theta <56^{\prime }$ for $\xi _+$ and $28^{\prime }<\theta <178^{\prime }$ for $\xi _-$. We perform the standard Bayesian likelihood analysis for cosmological inference from the measured cosmic shear TPCFs, including contributions from intrinsic alignment of galaxies as well as systematic effects from PSF model errors, shear calibration uncertainty, and source redshift distribution errors. We adopt a covariance matrix derived from realistic mock catalogs constructed from full-sky gravitational lensing simulations that fully account for survey geometry and measurement noise. For a flat $\Lambda$ cold dark matter model, we find $S\,_8 \equiv \sigma _8\sqrt{\Omega _{\rm m}/0.3}=0.804_{-0.029}^{+0.032}$, and $\Omega _{\rm m}=0.346_{-0.100}^{+0.052}$. We carefully check the robustness of the cosmological results against astrophysical modeling uncertainties and systematic uncertainties in measurements, and find that none of them has a significant impact on the cosmological constraints.

Phase-space correlation functions and isolating integrals

1984 ◽  
Vol 281 ◽  
pp. 473 ◽  
Author(s):  
P. Carnevali ◽  
P. Santangelo
Keyword(s):  
Phase Space ◽  
Correlation Functions ◽  
Space Correlation
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