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Related papers: Non-Gaussian error bars in galaxy surveys -- II

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We demonstrate the effectiveness of a relatively straightforward analysis of the complex 3D Fourier transform of galaxy coordinates derived from redshift surveys. Numerical demonstrations of this approach are carried out on a volume-limited…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-07 Jeffrey D. Scargle , Michael Way , Paul Gazis

Next-generation galaxy and 21cm intensity mapping surveys will rely on a combination of the power spectrum and bispectrum for high-precision measurements of primordial non-Gaussianity. In turn, these measurements will allow us to…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-08 Roy Maartens , Sheean Jolicoeur , Obinna Umeh , Eline M. De Weerd , Chris Clarkson

The next generation of galaxy surveys has the potential to substantially deepen our understanding of the Universe. This potential hinges on our ability to rigorously address systematic uncertainties. Until now, diagnosing systematic effects…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-18 Tristan Hoellinger , Florent Leclercq

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…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-19 Cullan Howlett

We study an observational method to analyze non-Gaussianity of a gravitational wave (GW) background made by superposition of weak burst signals. The proposed method is based on fourth-order correlations of data from four detectors, and…

General Relativity and Quantum Cosmology · Physics 2009-09-02 Naoki Seto

We present a simple and accurate method to constrain galaxy bias based on the distribution of counts in cells. The most unique feature of our technique is that it is applicable to non-linear scales, where both dark matter statistics and the…

Astrophysics · Physics 2009-11-10 Istvan Szapudi , Jun Pan

A non-Gaussian detection in the WMAP 1-year data is reported. The detection has been found in the combined Q-V-W map proposed by the WMAP team (Komatsu et al. 2003) after applying a wavelet technique based on the Spherical Mexican Hat…

Astrophysics · Physics 2008-11-26 P. Vielva , E. Martinez-Gonzalez , R. B. Barreiro , J. L. Sanz , L. Cayon

We describe a new method of overcoming problems inherent in peculiar velocity surveys by using data compression as a filter with which to separate large-scale, linear flows from small-scale noise that biases the results systematically. We…

Astrophysics · Physics 2007-05-23 Hume A Feldman , Richard Watkins , Adrian Melott , Will Chambers

One of the main signatures of primordial non-Gaussianity of the local type is a scale-dependent correction to the bias of large-scale structure tracers such as galaxies or clusters, whose amplitude depends on the bias of the tracers itself.…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-11 Nico Hamaus , Uros Seljak , Vincent Desjacques

A convincing detection of primordial non-Gaussianity in the cosmic background radiation (CMB) is essential to probe the physics of the early universe. Since a single statistical estimator can hardly be suitable to detect the various…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-11 W. Cardona , A Bernui , M. J. Reboucas

Tighter constraints on measurements of primordial non-Gaussianity will allow the differentiation of inflationary scenarios. The cosmic microwave background bispectrum-the standard method of measuring the local non-Gaussianity-is limited by…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-15 Zahra Gomes , Stefano Camera , Matt J. Jarvis , Catherine Hale , José Fonseca

We forecast constraints on primordial non-Gaussianity (PNG) and bias parameters from measurements of galaxy power spectrum and bispectrum in future radio continuum and optical surveys. In the galaxy bispectrum, we consider a comprehensive…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-04 Dionysios Karagiannis , Andrei Lazanu , Michele Liguori , Alvise Raccanelli , Nicola Bartolo , Licia Verde

Gaussianity is the very base for derivation of the cosmological parameters from the CMB angular power spectrum. Non-Gaussian signal, whether originated from experimental error or primordial source, could mimic extra power in the power…

Astrophysics · Physics 2009-11-11 Pavel Naselsky , Lung-Yih Chiang , Poul Olesen , Igor Novikov

Analyses of peculiar velocity surveys face several challenges, including low signal--to--noise in individual velocity measurements and the presence of small--scale, nonlinear flows. This is the second in a series of papers in which we…

Astrophysics · Physics 2009-11-07 Hume A. Feldman , Richard Watkins , Adrian L. Melott , Scott W. Chambers

We present and test a method that dramatically reduces variance arising from the sparse sampling of wavemodes in cosmological simulations. The method uses two simulations which are fixed (the initial Fourier mode amplitudes are fixed to the…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-27 Raul E. Angulo , Andrew Pontzen

Using 1000 ray-tracing simulations for a {\Lambda}-dominated cold dark model in Sato et al. (2009), we study the covariance matrix of cosmic shear correlation functions, which is the standard statistics used in the previous measurements.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Masanori Sato , Masahiro Takada , Takashi Hamana , Takahiko Matsubara

We present methods to rigorously extract parameter combinations that are constrained by data from posterior distributions. The standard approach uses linear methods that apply to Gaussian distributions. We show the limitations of the linear…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-06 Tara Dacunha , Marco Raveri , Minsu Park , Cyrille Doux , Bhuvnesh Jain

We consider cosmological models in which dark matter feels a fifth force mediated by the dark energy scalar field, also known as coupled dark energy. Our interest resides in estimating forecasts for future surveys like Euclid when we take…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-02 Santiago Casas , Luca Amendola , Marco Baldi , Valeria Pettorino , Adrian Vollmer

Forecasts and analyses of cosmological observations often rely on the assumption of a perfect theoretical model over a defined range of scales. We explore how model uncertainties and nuisance parameters in perturbative models of the matter…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-02 Tobias Baldauf , Mehrdad Mirbabayi , Marko Simonović , Matias Zaldarriaga

Using a discrete wavelet based space-scale decomposition (SSD), the spectrum of the skewness and kurtosis is developed to describe the non-Gaussian signatures in cosmologically interesting samples. Because the basis of the discrete wavelet…

Astrophysics · Physics 2007-05-23 Jesus Pando , Li-Zhi Fang