Cosmological measurements from angular power spectra analysis of BOSS DR12 tomography

Loureiro, A.; Moraes, Bruno; Abdalla, F. B.; Cuceu, Andrei; McLeod, Michael; Whiteway, L.; Balan, Sreekumar T.; Benoit-Lévy, A.; Lahav, O.; Manera, Marc; Rollins, R. P.; Xavier, H. S.

doi:10.1093/mnras/stz191

Cited by 63 publications

(72 citation statements)

References 113 publications

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“…It seems however that a consensus on the subject has not been reached, considering that cosmology-dependent covariance matrices are utilised in the angular power spectrum analysis of the BOSS-DR12 data (Loureiro et al 2019 Fig. 10.…”

Section: Dependence On Cosmologymentioning

confidence: 99%

Cosmic shear covariance matrix in wCDM: Cosmology matters

Harnois-Déraps

Giblin

Joachimi

2019

A&A

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We present here the cosmo-SLICS, a new suite of simulations specially designed for the analysis of current and upcoming weak lensing data beyond the standard two-point cosmic shear. We sample the [Ω m , σ 8 , h, w 0 ] parameter space at 25 points organised in a Latin hyper-cube, spanning a range that contains most of the 2σ posterior distribution from ongoing lensing surveys. At each of these nodes we evolve a pair of N-body simulations in which the sampling variance is highly suppressed, and ray-trace the volumes 800 times to further increase the effective sky coverage. We extract a lensing covariance matrix from these pseudo-independent lightcones and show that it closely matches a brute-force construction based on an ensemble of 800 truly independent N-body runs. More precisely, a Fisher analysis reveals that both methods yield marginalized two-dimensional constraints that vary by less than 6% in area, a result that holds under different survey specifications and that matches to within 15% the area obtained from an analytical covariance calculation. Extending this comparison with our 25 wCDM models, we probe the cosmology dependence of the lensing covariance directly from numerical simulations, reproducing remarkably well the Fisher results from the analytical models at most cosmologies. We demonstrate that varying the cosmology at which the covariance matrix is evaluated in the first place might have an order of magnitude greater impact on the parameter constraints than varying the choice of covariance estimation technique. We present a test case in which we generate fast predictions for both the lensing signal and its associated variance with a flexible Gaussian process regression emulator, achieving an accuracy of a few percent on the former and 10% on the latter.

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Section: Dependence On Cosmologymentioning

confidence: 99%

Cosmic shear covariance matrix in wCDM: Cosmology matters

Harnois-Déraps

Giblin

Joachimi

2019

A&A

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“…For each of these models, N ν is fixed to a specific value and m ν is sampled. Model 5 is a NH approximation with N ν = 1; i.e., we approximate the two lower mass neutrino species to m 1 = m 2 = 0 [17,22,23,28,29]. Next, in a similar way, model 6 is an IH approximation, where the lightest neutrino species is considered to be massless, which implies that N ν = 2 [26,29].…”

mentioning

confidence: 99%

“…[42] as presented in Ref. [22]. This sample is divided into 13 tomographic bins of ∆z = 0.05 in a redshift range of 0.15 < z < 0.80 containing a total of ∼ 1.15M spectroscopic galaxies over more than 9000 deg 2 in the sky.…”

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confidence: 99%

Upper Bound of Neutrino Masses from Combined Cosmological Observations and Particle Physics Experiments

et al. 2019

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We investigate the impact of prior models on the upper bound of the sum of neutrino masses, mν . Using data from large scale structure of galaxies, cosmic microwave background, type Ia supernovae, and big bang nucleosynthesis, we argue that cosmological neutrino mass and hierarchy determination should be pursued using exact models, since approximations might lead to incorrect and nonphysical bounds. We compare constraints from physically motivated neutrino mass models (i.e., ones respecting oscillation experiments) to those from models using standard cosmological approximations. The former give a consistent upper bound of mν 0.26 eV (95% CI) and yield the first approximation-independent upper bound for the lightest neutrino mass species, m ν 0 < 0.086 eV (95% CI). By contrast, one of the approximations, which is inconsistent with the known lower bounds from oscillation experiments, yields an upper bound of mν 0.15 eV (95% CI); this differs substantially from the physically motivated upper bound.

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“…These efforts were aimed at improving the survey's reach toward the largest scales ( 20), commonly distrusted in cosmological analyses (e.g. [34,35]). Finally, we also verified the impact of different assumptions about photo-z properties on the measured parameters.This work adds to previous WSC analyses that have investigated its observational and cosmological properties, such as hemispherical anisotropies [36], Minkowski functionals [37], cross-correlation with CMB lensing [38,39] and temperature [40].…”

mentioning

confidence: 99%

“…Finally, we also verified the impact of different assumptions about photo-z properties on the measured parameters.This work adds to previous WSC analyses that have investigated its observational and cosmological properties, such as hemispherical anisotropies [36], Minkowski functionals [37], cross-correlation with CMB lensing [38,39] and temperature [40]. It also contributes with a new strategy for mitigating systematics to those previously proposed [41][42][43][44][45][46].The basic technique we employ here -the measurement of angular power spectra in tomographic redshift shells -has been applied before to other photometric galaxy catalogs such as the MegaZ [47] and the 2MASS Photometric Redshift datasets (2MPZ) [34], to photometric quasar samples [42] and spectroscopic galaxy data [35].The outline of this paper is as follows: in Sec. 2 we describe the datasets used in this work, namely the WSC, the Sloan Digital Sky Survey, and the Gaia Data Release 2 catalogs.…”

mentioning

confidence: 99%

All-sky angular power spectra from cleaned WISE×SuperCOSMOS galaxy number counts

Xavier

Costa-Duarte

Balaguera-Antolínez

et al. 2019

J. Cosmol. Astropart. Phys.

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Aiming to extract cosmological information from linear scales of the WISE×SuperCOSMOS photometric redshift catalog, we perform a characterization of the systematic effects associated with stellar content, evidencing the presence of contamination and obscuration. We create an integrated model for these effects (which together we call "usurper contamination"), devise a method to remove both of them simultaneously and show its functionality by applying it to a set of mock catalogs. When administered to WISE×SuperCOSMOS data, our method shows to improve the measurements of angular power spectra on scales 15 and the extraction of cosmological parameters therefrom, even though a significant excess of power remains at these scales. When ignoring scales < 15, we still find strong indications of systematics, albeit these can be localized in the southern equatorial hemisphere. An independent analysis of the northern hemisphere at ≥ 15 agrees with the ΛCDM model with parameters from the Planck satellite and gives Ω c = 0.254 ± 0.020 and Ω b < 0.065 at 95% confidence limit when combined with priors on H 0 , A s and n s . lensing of the cosmic microwave background (CMB) -which serves as a consistency check for our cosmological model, besides helping improve constraints on halo bias and on the amplitude of matter perturbationspeaks at large angular scales [25]. This is also the case for the integrated Sachs-Wolfe effect [26], probed by the cross-correlation of CMB temperature maps with galaxy distribution, whose signal comes from the evolution of gravitational potential along the CMB photon path. Another topic that requires almost full-sky galaxy surveys is the measurement of our own peculiar velocity with respect to all other galaxies [27][28][29]. Large galaxy surveys can also help us improve our understanding of galaxy bias, that could be enhanced at the largest scales if we assume that galaxies form at density peaks (see e.g. [30]).This type of studies are among the main aims of the largest forthcoming surveys. The Large Synoptic Survey Telescope 1 (LSST) [31] will cover 18, 000 deg 2 up to redshifts z 3, while the Euclid space telescope 2 will observe 15,000 deg 2 and detect galaxies up to z 2 [32]. The huge volume probed by these surveys will lead to such a high number of observed galaxies and quasars that spectroscopic measurements will be performed only for a small fraction of them, while for most sources we will have to rely on photometric redshifts (photo-zs hereafter) and photometric classification. These techniques are, however, plagued with high contamination levels, large systematic effects and uncertainties, which must be controlled and understood in order to fully mine the relevant datasets.An existing testbed for such surveys is the WISE×SuperCOSMOS catalog [33] (WSC hereafter), a fullsky photometric galaxy dataset reaching z 0.4. Our goal in this paper is to estimate cosmological parameters from this sample under the standard cosmological model ΛCDM. In this process, we characterize the systematic effects ass...

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Cosmological measurements from angular power spectra analysis of BOSS DR12 tomography

Cited by 63 publications

References 113 publications

Cosmic shear covariance matrix in wCDM: Cosmology matters

Cosmic shear covariance matrix in wCDM: Cosmology matters

Upper Bound of Neutrino Masses from Combined Cosmological Observations and Particle Physics Experiments

All-sky angular power spectra from cleaned WISE×SuperCOSMOS galaxy number counts

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