Luminous Red Galaxy Halo Density Field Reconstruction and Application to Large-Scale Structure Measurements

Reid, Beth; Spergel, David N.; Bode, Paul

doi:10.1088/0004-637x/702/1/249

Cited by 38 publications

(70 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(15) overestimates the beat-coupling effect. This conclusion agrees with a recent study of Reid, Spergel & Bode (2008), where they showed that the simulation results are fairly well explained if Eq. (15) reduced by a factor 3 is added to the Gaussian covariance.…”

Section: Effects Of Long-wavelength Fluctuationssupporting

confidence: 93%

Simulations of Baryon Acoustic Oscillations. Ii. Covariance Matrix of the Matter Power Spectrum

Takahashi

Yoshida

Takada

et al. 2009

ApJ

135

190

View full text Add to dashboard Cite

We use 5000 cosmological N -body simulations of 1h −3 Gpc 3 box for the concordance ΛCDM model in order to study the sampling variances of nonlinear matter power spectrum. We show that the non-Gaussian errors can be important even on large length scales relevant for baryon acoustic oscillations (BAO). Our findings are (1) the non-Gaussian errors degrade the cumulative signal-to-noise ratios (S/N ) for the power spectrum amplitude by up to a factor of 2 and 4 for redshifts z = 1 and 0, respectively. (2) There is little information on the power spectrum amplitudes in the quasinonlinear regime, confirming the previous results. (3) The distribution of power spectrum estimators at BAO scales, among the realizations, is well approximated by a Gaussian distribution with variance that is given by the diagonal covariance component. (4) For the redshift-space power spectrum, the degradation in S/N by non-Gaussian errors is mitigated due to nonlinear redshift distortions. (5) For an actual galaxy survey, the additional shot noise contamination compromises the cosmological information inherent in the galaxy power spectrum, but also mitigates the impact of non-Gaussian errors. The S/N is degraded by up to 30% for a WFMOS-type survey. (6) The finite survey volume causes additional non-Gaussian errors via the correlations of long-wavelength fluctuations with the fluctuations we want to measure, further degrading the S/N values by about 30% even at high redshift z = 3.

show abstract

Section: Effects Of Long-wavelength Fluctuationssupporting

confidence: 93%

Simulations of Baryon Acoustic Oscillations. Ii. Covariance Matrix of the Matter Power Spectrum

Takahashi

Yoshida

Takada

et al. 2009

ApJ

135

190

View full text Add to dashboard Cite

show abstract

“…Thus they are frequently used as an efficient tracer of large scale structure. Furthermore, since the LRGs have been shown to live in the most massive haloes of the Universe [10,28,29,63], they can be effectively probed with our N -body simulations.…”

Section: Reference Samplementioning

confidence: 99%

Algorithm for the direct reconstruction of the dark matter correlation function from weak lensing and galaxy clustering

et al. 2010

View full text Add to dashboard Cite

The clustering of matter on cosmological scales is an essential probe for studying the physical origin and composition of our Universe. To date, most of the direct studies have focused on shear-shear weak lensing correlations, but it is also possible to extract the dark matter clustering by combining galaxy-clustering and galaxy-galaxy-lensing measurements. In order to extract the required information, one must relate the observable galaxy distribution to the underlying dark matter distribution. In this study we develop in detail a method that can constrain the dark matter correlation function from galaxy clustering and galaxy-galaxy-lensing measurements, by focusing on the correlation coefficient between the galaxy and matter overdensity fields. Our goal is to develop an estimator that maximally correlates the two. To generate a mock galaxy catalogue for testing purposes, we use the halo occupation distribution approach applied to a large ensemble of N-body simulations to model preexisting SDSS luminous red galaxy sample observations. Using this mock catalogue, we show that a direct comparison between the excess surface mass density measured by lensing and its corresponding galaxy clustering quantity is not optimal. We develop a new statistic that suppresses the small-scale contributions to these observations and show that this new statistic leads to a cross-correlation coefficient that is within a few percent of unity down to 5h-1Mpc. Furthermore, the residual incoherence between the galaxy and matter fields can be explained using a theoretical model for scale-dependent galaxy bias, giving us a final estimator that is unbiased to within 1%, so that we can reconstruct the dark matter clustering power spectrum at this accuracy up to ktilde;1hMpc-1. We also perform a comprehensive study of other physical effects that can affect the analysis, such as redshift space distortions and differences in radial windows between galaxy clustering and weak lensing observations. We apply the method to a range of cosmological models and explicitly show the viability of our new statistic to distinguish between cosmological models. An algorithm for the direct reconstruction of the dark matter correlation function from weak lensing and galaxy clustering The clustering of matter on cosmological scales is an essential probe for studying the physical origin and composition of our Universe. To date, most of the direct studies have focused on shear-shear weak lensing correlations, but it is also possible to extract the dark matter clustering by combining galaxy-clustering and galaxy-galaxy-lensing measurements. In order to extract the required information, one must relate the observable galaxy distribution to the underlying dark matter distribution. In this study we develop in detail a method that can constrain the dark matter correlation function from galaxy clustering and galaxy-galaxy-lensing measurements, by focusing on the correlation coefficient between the galaxy and matter overdensity fields. Our goal is to develop an...

show abstract

“…While some such studies have been performed (see e.g. [24,25]), a systematic study, leading to a complete and well tested analytic description has until now been lacking.…”

Section: Introductionmentioning

confidence: 99%

Thinking outside the box: effects of modes larger than the survey on matter power spectrum covariance

Putter

Wagner

Mena

et al. 2012

J. Cosmol. Astropart. Phys.

View full text Add to dashboard Cite

Accurate power spectrum (or correlation function) covariance matrices are a crucial requirement for cosmological parameter estimation from large scale structure surveys. In order to minimize reliance on computationally expensive mock catalogs, it is important to have a solid analytic understanding of the different components that make up a covariance matrix. Considering the matter power spectrum covariance matrix, it has recently been found that there is a potentially dominant effect on mildly non-linear scales due to power in modes of size equal to and larger than the survey volume. This beat coupling effect has been derived analytically in perturbation theory and while it has been tested with simulations, some questions remain unanswered. Moreover, there is an additional effect of these large modes, which has so far not been included in analytic studies, namely the effect on the estimated average density which enters the power spectrum estimate. In this article, we work out analytic, perturbation theory based expressions including both the beat coupling and this local average effect and we show that while, when isolated, beat coupling indeed causes large excess covariance in agreement with the literature, in a realistic scenario this is compensated almost entirely by the local average effect, leaving only ∼ 10% of the excess. We test our analytic expressions by comparison to a suite of large N-body simulations, using both full simulation boxes and subboxes thereof to study cases without beat coupling, with beat coupling and with both beat coupling and the local average effect. For the variances, we find excellent agreement with the analytic expressions for k < 0.2hMpc −1 at z = 0.5, while the correlation coefficients agree to beyond k = 0.4hMpc −1 . As expected, the range of agreement increases towards higher redshift and decreases slightly towards z = 0. We finish by including the large-mode effects in a full covariance matrix description for arbitrary survey geometry and confirming its validity using simulations. This may be useful as a stepping stone towards building an actual galaxy (or other tracer's) power spectrum covariance matrix.

show abstract

Luminous Red Galaxy Halo Density Field Reconstruction and Application to Large-Scale Structure Measurements

Cited by 38 publications

References 45 publications

Simulations of Baryon Acoustic Oscillations. Ii. Covariance Matrix of the Matter Power Spectrum

Simulations of Baryon Acoustic Oscillations. Ii. Covariance Matrix of the Matter Power Spectrum

Algorithm for the direct reconstruction of the dark matter correlation function from weak lensing and galaxy clustering

Thinking outside the box: effects of modes larger than the survey on matter power spectrum covariance

Contact Info

Product

Resources

About