Measuring the Galaxy Power Spectrum with Multiresolution Decomposition. II. Diagonal and Off‐Diagonal Power Spectra of the Las Campanas Redshift Survey Galaxies

2001 ◽  
Vol 553 (1) ◽  
pp. 1-13 ◽  
Author(s):  
XiaoHu Yang ◽  
Long‐Long Feng ◽  
YaoQuan Chu ◽  
Li‐Zhi Fang
Keyword(s):  
Power Spectrum ◽  
Power Spectra ◽  
Multiresolution Decomposition ◽  
The Galaxy ◽  
Redshift Survey

Measuring the Galaxy Power Spectrum with Multiresolution Decomposition. IV. Redshift Distortion

2002 ◽  
Vol 566 (2) ◽  
pp. 630-640 ◽  
Author(s):  
XiaoHu Yang ◽  
Long‐Long Feng ◽  
YaoQuan Chu ◽  
Li‐Zhi Fang
Keyword(s):  
Power Spectrum ◽  
Multiresolution Decomposition ◽  
The Galaxy

scholarly journals The redshift-space momentum power spectrum – I. Optimal estimation from peculiar velocity surveys

2019 ◽  
Vol 487 (4) ◽  
pp. 5209-5234 ◽  
Author(s):  
Cullan Howlett
Keyword(s):  
Power Spectrum ◽  
Measurement Errors ◽  
Cosmological Parameters ◽  
Power Spectra ◽  
Optimal Estimation ◽  
Peculiar Velocity ◽  
Optimal Weights ◽  
Peculiar Velocities ◽  
Redshift Surveys ◽  
The Galaxy

Abstract Low redshift surveys of galaxy peculiar velocities provide a wealth of cosmological information. We revisit the idea of extracting this information by directly measuring the redshift-space momentum power spectrum from such surveys. We provide a comprehensive theoretical and practical framework for estimating and fitting this from data, analogous to well-understood techniques used to measure the galaxy density power spectrum from redshift surveys. We formally derive a new estimator, which includes the effects of shot noise and survey geometry; we evaluate the variance of the estimator in the Gaussian regime; we compute the optimal weights for the estimator; we demonstrate that the measurements are Gaussian distributed, allowing for easy extraction of cosmological parameters; and we explore the effects of peculiar velocity (PV) measurement errors. We finish with a proof-of-concept using realistic mock galaxy catalogues, which demonstrates that we can measure and fit both the redshift-space galaxy density and momentum power spectra from PV surveys and that including the latter substantially improves our constraints on the growth rate of structure. We also provide theoretical descriptions for modelling the non-linear redshift-space density and momentum power spectrum multipoles, and forecasting the constraints on cosmological parameters using the Fisher information contained in these measurements for arbitrary weights. These may be useful for measurements of the galaxy density power spectrum even in the absence of peculiar velocities.

scholarly journals Gravitational Fluctuations as an Alternative to Inflation II. CMB Angular Power Spectrum

2019 ◽  
Author(s):  
Herbert W. Hamber ◽  
Lu Heng Sunny Yu
Keyword(s):  
Power Spectrum ◽  
Power Spectra ◽  
Angular Spectrum ◽  
Scalar Fields ◽  
Data Sets ◽  
Angular Power Spectrum ◽  
Fundamental Parameters ◽  
Matter Power Spectrum ◽  
The Galaxy ◽  
Cosmological Data

Power spectra always play an important role in the theory of inflation. In particular, the ability to reproduce the galaxy matter power spectrum $ P(k) $ and the CMB temperature angular power spectrum $ C_l $’s to high accuracy is often considered a triumph of inflation. In our previous work, we presented an alternative explanation for the matter power spectrum based on nonperturbative quantum field-theoretical methods applied to Einstein’s gravity, instead of inflation models based on scalar fields. In this work, we review the basic concepts and provide further in-depth investigations. We first update the analysis with more recent data sets and error analysis, and then extend our predictions to the CMB angular spectrum coefficients $ C_l $, which we did not consider previously. Then we investigate further the potential freedoms and uncertainties associated with the fundamental parameters that are part of this picture, and show how recent cosmological data provides significant constraints on these quantities. Overall, we find good general consistency between theory and data, even potentially favoring the gravitationally-motivated picture at the largest scales. We summarize our results by outlining how this picture can be tested in the near future with increasingly accurate astrophysical measurements.

scholarly journals Measuring the Galaxy Power Spectrum with Multiresolution Decomposition. III. Velocity Field Analysis

2001 ◽  
Vol 560 (2) ◽  
pp. 549-565 ◽  
Author(s):  
Xiao Hu Yang ◽  
Long‐Long Feng ◽  
Yao Quan Chu ◽  
Li‐Zhi Fang
Keyword(s):  
Velocity Field ◽  
Power Spectrum ◽  
Field Analysis ◽  
Multiresolution Decomposition ◽  
The Galaxy

scholarly journals Mitigating contamination in LSS surveys: a comparison of methods

2021 ◽  
Vol 503 (4) ◽  
pp. 5061-5084 ◽  
Author(s):  
Noah Weaverdyck ◽  
Dragan Huterer
Keyword(s):  
Power Spectrum ◽  
Large Scale ◽  
Power Spectra ◽  
Dark Energy Survey ◽  
Current State ◽  
Galaxy Distribution ◽  
The Galaxy ◽  
Improved Estimators ◽  
Mitigation Methods ◽  
Energy Survey

ABSTRACT Future large-scale structure surveys will measure the locations and shapes of billions of galaxies. The precision of such catalogues will require meticulous treatment of systematic contamination of the observed fields. We compare several existing methods for removing such systematics from galaxy clustering measurements. We show how all the methods, including the popular pseudo-Cℓ Mode Projection and Template Subtraction methods, can be interpreted under a common regression framework and use this to suggest improved estimators. We show how methods designed to mitigate systematics in the power spectrum can be used to produce clean maps, which are necessary for cosmological analyses beyond the power spectrum, and we extend current methods to treat the next-order multiplicative contamination in observed maps and power spectra, which reduced power spectrum errors from $\Delta \chi ^2_{\rm C_\ell }\simeq 10$ to ≃ 1 in simulated analyses. Two new mitigation methods are proposed, which incorporate desirable features of current state-of-the-art methods while being simpler to implement. Investigating the performance of all the methods on a common set of simulated measurements from Year 5 of the Dark Energy Survey, we test their robustness to various analysis cases. Our proposed methods produce improved maps and power spectra when compared to current methods, while requiring almost no user tuning. We end with recommendations for systematics mitigation in future surveys, and note that the methods presented are generally applicable beyond the galaxy distribution to any field with spatial systematics.

scholarly journals Measuring the VIPERS galaxy power spectrum at $z\sim1$

2014 ◽  
Vol 11 (S308) ◽  
pp. 169-171
Author(s):  
Stefano Rota ◽  
Julien Bel ◽  
Ben Granett ◽  
Luigi Guzzo
Keyword(s):  
Power Spectrum ◽  
Matter Density ◽  
Spatial Sampling ◽  
Volume Number ◽  
Galaxy Distribution ◽  
Data Release ◽  
The Galaxy ◽  
Redshift Survey ◽  
First Time ◽  
The Universe

AbstractThe VIMOS Public Extragalactic Redshift Survey [VIPERS, Guzzo et al. 2014] is using the VIMOS spectrograph at the ESO VLT to measure redshifts for ∼ 100,000 galaxies with IAB < 22.5 and 0.5 < z < 1.2, over an area of 24 deg2 (split over the W1 and W4 fields of CFHTLS). VIPERS currently provides, at such redshifts, the best compromise between volume, number of galaxies and dense spatial sampling. We present here the first estimate of the power spectrum of the galaxy distribution, P(k), at redshifts z ∼ 0.75 and z ∼ 1, obtained from the ∼ 55,000 redshifts of the PDR-1 data release. We discuss first constraints on cosmological quantities, as the matter density and the baryonic fraction, obtained for the first time at an epoch when the Universe was about half its current age.

scholarly journals Unified galaxy power spectrum measurements from 6dFGS, BOSS, and eBOSS

2021 ◽  
Vol 2021 (11) ◽  
pp. 031
Author(s):  
Florian Beutler ◽  
Patrick McDonald
Keyword(s):  
Power Spectrum ◽  
Power Spectra ◽  
Acoustic Oscillation ◽  
Window Function ◽  
Wide Angle ◽  
Standard Analysis ◽  
Redshift Surveys ◽  
Spectrum Measurements ◽  
The Galaxy ◽  
Recent Developments

Abstract We make use of recent developments in the analysis of galaxy redshift surveys to present an easy to use matrix-based analysis framework for the galaxy power spectrum multipoles, including wide-angle effects and the survey window function. We employ this framework to derive the deconvolved power spectrum multipoles of 6dFGS DR3, BOSS DR12 and the eBOSS DR16 quasar sample. As an alternative to the standard analysis, the deconvolved power spectrum multipoles can be used to perform a data analysis agnostic of survey specific aspects, like the window function. We show that in the case of the BOSS dataset, the Baryon Acoustic Oscillation (BAO) analysis using the deconvolved power spectra results in the same likelihood as the standard analysis. To facilitate the analysis based on both the convolved and deconvolved power spectrum measurements, we provide the window function matrices, wide-angle matrices, covariance matrices and the power spectrum multipole measurements for the datasets mentioned above. Together with this paper we publish a Python-based toolbox to calculate the different analysis components. The appendix contains a detailed user guide with examples for how a cosmological analysis of these datasets could be implemented. We hope that our work makes the analysis of galaxy survey datasets more accessible to the wider cosmology community.

scholarly journals Neutrino masses from CMB B-mode polarization and cosmic growth rate

2015 ◽  
Vol 30 (01) ◽  
pp. 1550001 ◽  
Author(s):  
Koichi Hirano
Keyword(s):  
Growth Rate ◽  
Monte Carlo ◽  
Power Spectrum ◽  
Neutrino Masses ◽  
Mcmc Method ◽  
Microwave Background ◽  
The Galaxy ◽  
Redshift Survey ◽  
Galaxy Bias ◽  
Planck Satellite

Constraints on neutrino masses are estimated based on future observations of the cosmic microwave background (CMB), which includes the B-mode polarization produced by CMB lensing from the Planck satellite, and the growth rate of cosmic structure from the Euclid redshift survey by using the Markov–Chain Monte-Carlo (MCMC) method. The error in the bound on the total neutrino mass is estimated to be Δ ∑ mν = 0.075 eV with a 68% confidence level. By using the growth rate rather than the galaxy power spectrum, accurate constraints are obtained, since the growth rate is less influenced by the uncertainty regarding galaxy bias than by the galaxy power spectrum.

scholarly journals Gravitational Fluctuations as an Alternative to Inflation II. CMB Angular Power Spectrum

Universe ◽  
2019 ◽  
Vol 5 (11) ◽  
pp. 216 ◽  
Author(s):  
Herbert W. Hamber ◽  
Lu Heng Sunny Yu
Keyword(s):  
Power Spectrum ◽  
Power Spectra ◽  
Angular Spectrum ◽  
Scalar Fields ◽  
Data Sets ◽  
Angular Power Spectrum ◽  
Fundamental Parameters ◽  
Matter Power Spectrum ◽  
The Galaxy ◽  
Cosmological Data

Power spectra always play an important role in the theory of inflation. In particular, the ability to reproduce the galaxy matter power spectrum P ( k ) and the CMB temperature angular power spectrum C l ’s to high accuracy is often considered a triumph of inflation. In our previous work, we presented an alternative explanation for the matter power spectrum based on nonperturbative quantum field-theoretical methods applied to Einstein’s gravity, instead of inflation models based on scalar fields. In this work, we review the basic concepts and provide further in-depth investigations. We first update the analysis with more recent data sets and error analysis, and then extend our predictions to the CMB angular spectrum coefficients C l , which we did not consider previously. Then we investigate further the potential freedoms and uncertainties associated with the fundamental parameters that are part of this picture, and show how recent cosmological data provides significant constraints on these quantities. Overall, we find good general consistency between theory and data, even potentially favoring the gravitationally-motivated picture at the largest scales. We summarize our results by outlining how this picture can be tested in the near future with increasingly accurate astrophysical measurements.

Measuring the Galaxy Power Spectrum with Multiresolution Decomposition

2006 ◽  
pp. 401-402
Author(s):  
Yaoquan Chu ◽  
XiaoHu Yang ◽  
Long-Long Feng ◽  
Li-Zhi Fang
Keyword(s):  
Power Spectrum ◽  
Multiresolution Decomposition ◽  
The Galaxy
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