scholarly journals Probing correlated compensated isocurvature perturbations using scale-dependent galaxy bias

2019 ◽  
Vol 100 (10) ◽  
Author(s):  
Selim C. Hotinli ◽  
James B. Mertens ◽  
Matthew C. Johnson ◽  
Marc Kamionkowski
Keyword(s):  
Galaxy Bias ◽  
Isocurvature Perturbations

scholarly journals Scale dependence of galaxy biasing investigated by weak gravitational lensing: An assessment using semi-analytic galaxies and simulated lensing data

2018 ◽  
Vol 613 ◽  
pp. A15 ◽  
Author(s):  
Patrick Simon ◽  
Stefan Hilbert
Keyword(s):  
Gravitational Lensing ◽  
Spatial Scales ◽  
Scale Dependence ◽  
Reconstruction Technique ◽  
Weak Gravitational Lensing ◽  
Physical Scale ◽  
The Galaxy ◽  
Galaxy Bias ◽  
The Impact ◽  
Lens Galaxies

Galaxies are biased tracers of the matter density on cosmological scales. For future tests of galaxy models, we refine and assess a method to measure galaxy biasing as a function of physical scalekwith weak gravitational lensing. This method enables us to reconstruct the galaxy bias factorb(k) as well as the galaxy-matter correlationr(k) on spatial scales between 0.01hMpc−1≲k≲ 10hMpc−1for redshift-binned lens galaxies below redshiftz≲ 0.6. In the refinement, we account for an intrinsic alignment of source ellipticities, and we correct for the magnification bias of the lens galaxies, relevant for the galaxy-galaxy lensing signal, to improve the accuracy of the reconstructedr(k). For simulated data, the reconstructions achieve an accuracy of 3–7% (68% confidence level) over the abovek-range for a survey area and a typical depth of contemporary ground-based surveys. Realistically the accuracy is, however, probably reduced to about 10–15%, mainly by systematic uncertainties in the assumed intrinsic source alignment, the fiducial cosmology, and the redshift distributions of lens and source galaxies (in that order). Furthermore, our reconstruction technique employs physical templates forb(k) andr(k) that elucidate the impact of central galaxies and the halo-occupation statistics of satellite galaxies on the scale-dependence of galaxy bias, which we discuss in the paper. In a first demonstration, we apply this method to previous measurements in the Garching-Bonn Deep Survey and give a physical interpretation of the lens population.

scholarly journals Relaxation leptogenesis, isocurvature perturbations, and the cosmic infrared background

2017 ◽  
Vol 95 (10) ◽  
Author(s):  
Masahiro Kawasaki ◽  
Alexander Kusenko ◽  
Lauren Pearce ◽  
Louis Yang
Keyword(s):  
Infrared Background ◽  
Cosmic Infrared Background ◽  
Isocurvature Perturbations

scholarly journals CMB constraint on non-Gaussianity in isocurvature perturbations

2013 ◽  
Vol 2013 (07) ◽  
pp. 007-007 ◽  
Author(s):  
Chiaki Hikage ◽  
Masahiro Kawasaki ◽  
Toyokazu Sekiguchi ◽  
Tomo Takahashi
Keyword(s):  
Isocurvature Perturbations

scholarly journals Producing a BOSS CMASS sample with DES imaging

2019 ◽  
Vol 489 (2) ◽  
pp. 2887-2906 ◽  
Author(s):  
S Lee ◽  
E M Huff ◽  
A J Ross ◽  
A Choi ◽  
C Hirata ◽  
...  
Keyword(s):  
Sloan Digital Sky Survey ◽  
Joint Analysis ◽  
Dark Energy Survey ◽  
Sky Survey ◽  
Angular Correlation Function ◽  
Galaxy Sample ◽  
Celestial Equator ◽  
The Difference ◽  
Galaxy Bias ◽  
Validation Tests

ABSTRACT We present a sample of galaxies with the Dark Energy Survey (DES) photometry that replicates the properties of the BOSS CMASS sample. The CMASS galaxy sample has been well characterized by the Sloan Digital Sky Survey (SDSS) collaboration and was used to obtain the most powerful redshift-space galaxy clustering measurements to date. A joint analysis of redshift-space distortions (such as those probed by CMASS from SDSS) and a galaxy–galaxy lensing measurement for an equivalent sample from DES can provide powerful cosmological constraints. Unfortunately, the DES and SDSS-BOSS footprints have only minimal overlap, primarily on the celestial equator near the SDSS Stripe 82 region. Using this overlap, we build a robust Bayesian model to select CMASS-like galaxies in the remainder of the DES footprint. The newly defined DES-CMASS (DMASS) sample consists of 117 293 effective galaxies covering $1244\,\deg ^2$. Through various validation tests, we show that the DMASS sample selected by this model matches well with the BOSS CMASS sample, specifically in the South Galactic cap (SGC) region that includes Stripe 82. Combining measurements of the angular correlation function and the clustering-z distribution of DMASS, we constrain the difference in mean galaxy bias and mean redshift between the BOSS CMASS and DMASS samples to be $\Delta b = 0.010^{+0.045}_{-0.052}$ and $\Delta z = \left(3.46^{+5.48}_{-5.55} \right) \times 10^{-3}$ for the SGC portion of CMASS, and $\Delta b = 0.044^{+0.044}_{-0.043}$ and $\Delta z= (3.51^{+4.93}_{-5.91}) \times 10^{-3}$ for the full CMASS sample. These values indicate that the mean bias of galaxies and mean redshift in the DMASS sample are consistent with both CMASS samples within 1σ.

scholarly journals Cosmology with galaxy–galaxy lensing on non-perturbative scales: emulation method and application to BOSS LOWZ

2019 ◽  
Vol 492 (2) ◽  
pp. 2872-2896 ◽  
Author(s):  
Benjamin D Wibking ◽  
David H Weinberg ◽  
Andrés N Salcedo ◽  
Hao-Yi Wu ◽  
Sukhdeep Singh ◽  
...  
Keyword(s):  
Cosmological Parameters ◽  
Linear Structure ◽  
Sloan Digital Sky Survey ◽  
Projected Clustering ◽  
True Value ◽  
Data Release ◽  
Non Linear ◽  
Galaxy Sample ◽  
Galaxy Bias ◽  
Red Galaxies

ABSTRACT We describe our non-linear emulation (i.e. interpolation) framework that combines the halo occupation distribution (HOD) galaxy bias model with N-body simulations of non-linear structure formation, designed to accurately predict the projected clustering and galaxy–galaxy lensing signals from luminous red galaxies in the redshift range 0.16 < z < 0.36 on comoving scales 0.6 < rp < 30 $h^{-1} \, \text{Mpc}$. The interpolation accuracy is ≲ 1–2 per cent across the entire physically plausible range of parameters for all scales considered. We correctly recover the true value of the cosmological parameter S8 = (σ8/0.8228)(Ωm/0.3107)0.6 from mock measurements produced via subhalo abundance matching (SHAM)-based light-cones designed to approximately match the properties of the SDSS LOWZ galaxy sample. Applying our model to Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 14 (DR14) LOWZ galaxy clustering and galaxy-shear cross-correlation measurements made with Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8) imaging, we perform a prototype cosmological analysis marginalizing over wCDM cosmological parameters and galaxy HOD parameters. We obtain a 4.4 per cent measurement of S8 = 0.847 ± 0.037, in 3.5σ tension with the Planck cosmological results of 1.00 ± 0.02. We discuss the possibility of underestimated systematic uncertainties or astrophysical effects that could explain this discrepancy.

scholarly journals Measuring Galaxy Bias from the High-Order Correlation Functions

1999 ◽  
Vol 183 ◽  
pp. 229-234
Author(s):  
Y.P. Jing
Keyword(s):  
Correlation Functions ◽  
Cosmological Parameters ◽  
High Order ◽  
Density Parameter ◽  
Theoretical Argument ◽  
Important Conclusion ◽  
Point Correlation ◽  
Point Correlation Function ◽  
Redshift Survey ◽  
Galaxy Bias

In this talk, I will show how to determine the biasing factor b from the high-order moments of galaxies. The determination is based on the analytical modeling of primordial peaks and virialized halos and is independent of the currently unknown density parameter Ω0 and other cosmological parameters. The observed high-oder moments of the APM galaxies require that the biasing factor b be very close to 1, i.e. the optical galaxies are an unbiased tracer of the underlying mass distribution (on quasilinear scale). The theoretical argument can be easily generalized to the three-point correlation function and the bispectrum both of which can used as further observational tests to the important conclusion of b ≈ 1 drawn from the high-order moments. Finally I present our preliminary results of the three-point correlation functions for the Las Campanas Redshift Survey.

scholarly journals Baryon-CDM isocurvature galaxy bias with IllustrisTNG

2020 ◽  
Vol 2020 (02) ◽  
pp. 005-005 ◽  
Author(s):  
Alexandre Barreira ◽  
Giovanni Cabass ◽  
Dylan Nelson ◽  
Fabian Schmidt
Keyword(s):  
Galaxy Bias
Sign in / Sign up

Export Citation Format

Share Document