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The present spatial distribution of galaxies in the Universe is non-Gaussian, with 40% skewness in 50 Mpc/h spheres, and remarkably little is known about the information encoded in it about cosmological parameters beyond the power spectrum.…

Astrophysics · Physics 2008-11-26 Emiliano Sefusatti , Martin Crocce , Sebastian Pueblas , Roman Scoccimarro

To investigate and specify the statistical properties of cosmological fields with particular attention to possible non-Gaussian features, accurate formulae for the bispectrum and the bispectrum covariance are required. The bispectrum is the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Sandra Martin , Peter Schneider , Patrick Simon

Naive estimates of the statistics of large scale structure and weak lensing power spectrum measurements that include only Gaussian errors exaggerate their scientific impact. Non-linear evolution and finite volume effects are both…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-24 Emmanuel Schaan , Masahiro Takada , David N. Spergel

We undertake a thorough search for signatures of sharp oscillatory features in the WMAP9 power spectrum and bispectrum as well as in the Planck power spectrum. For the first time, we carry out searches in both the power spectrum and…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-27 J. R. Fergusson , H. F. Gruetjen , E. P. S. Shellard , B. Wallisch

Aims. We investigate the contribution of shot-noise and sample variance to the uncertainty of cosmological parameter constraints inferred from cluster number counts in the context of the Euclid survey. Methods. By analysing 1000 Euclid-like…

We describe an approximate statistical model for the sample variance distribution of the non-linear matter power spectrum that can be calibrated from limited numbers of simulations. Our model retains the common assumption of a multivariate…

We use the Fisher-matrix formalism to investigate whether the galaxy bispectrum in redshift space, $B$, contains additional cosmological information with respect to the power spectrum, $P$. We focus on a $Euclid$-like survey and consider…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-10 Victoria Yankelevich , Cristiano Porciani

Cosmological weak lensing by the large scale structure of the Universe, cosmic shear, is coming of age as a powerful probe of the parameters describing the cosmological model and matter power spectrum. It complements CMB studies, by…

Astrophysics · Physics 2009-11-10 Patrick Simon , Lindsay J. King , Peter Schneider

Cosmic shear is one of the most powerful probes of Dark Energy, targeted by several current and future galaxy surveys. Lensing shear, however, is only sampled at the positions of galaxies with measured shapes in the catalog, making its…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-31 Andrina Nicola , Carlos García-García , David Alonso , Jo Dunkley , Pedro G. Ferreira , Anže Slosar , David N. Spergel

Beyond the linear regime of structure formation, part of cosmological information encoded in galaxy clustering becomes inaccessible to the usual power spectrum. "Sufficient statistics", A*, were introduced recently to recapture the lost,…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 M. Wolk , J. Carron , I. Szapudi

We measure the halo bispectrum covariance in a large set of N-body simulations and compare it with theoretical expectations. We find a large correlation among (even mildly) squeezed halo bispectrum configurations. A similarly large…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-14 Matteo Biagetti , Lina Castiblanco , Jorge Noreña , Emiliano Sefusatti

We computed the power spectrum of weak cosmic shear in models with non-Gaussian primordial density fluctuations. Cosmological initial conditions deviating from Gaussianity have recently attracted much attention in the literature, especially…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 C. Fedeli , L. Moscardini

The estimation of cosmological constraints from observations of the large scale structure of the Universe, such as the power spectrum or the correlation function, requires the knowledge of the inverse of the associated covariance matrix,…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Dante J. Paz , Ariel G. Sanchez

As galaxy surveys become more precise and push to smaller scales, the need for accurate covariances beyond the classical Gaussian formula becomes more acute. Here, I investigate the analytical implementation and impact of non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-12 Fabien Lacasa

We study constraints on primordial mode-coupling from the power spectrum, squeezed-limit bispectrum and collapsed trispectrum of matter and halos. We describe these statistics in terms of long-wavelength $2$-point functions involving the…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-20 Roland de Putter

Fisher Information Matrix methods are commonly used in cosmology to estimate the accuracy that cosmological parameters can be measured with a given experiment, and to optimise the design of experiments. However, the standard approach…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 A. Kiessling , A. N. Taylor , A. F. Heavens

Measurements of the redshift-space galaxy clustering have been a prolific source of cosmological information in recent years. Accurate covariance estimates are an essential step for the validation of galaxy clustering models of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-17 Jan Niklas Grieb , Ariel G. Sánchez , Salvador Salazar-Albornoz , Claudio Dalla Vecchia

The forecasted accuracy of upcoming surveys of large-scale structure cannot be achieved without a proper quantification of the error induced by foreground removal (or other systematics like 0-point photometry offset). Because these errors…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-29 Manuel Colavincenzo , Pierluigi Monaco , Emiliano Sefusatti , Stefano Borgani

Cosmological parameter estimation requires that the likelihood function of the data is accurately known. Assuming that cosmological large-scale structure power spectra data are multivariate Gaussian-distributed, we show the accuracy of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Andy Taylor , Benjamin Joachimi , Thomas Kitching

In this study, we measure the response of matter and halo projected power spectra $P^{\rm 2D}_{\rm XY}(k)$ (X, Y are matter and/or halos), to a large-scale density contrast, $\delta_{\rm b}$, using separate universe simulations. We show…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-14 Ryuichi Takahashi , Takahiro Nishimichi , Masahiro Takada , Masato Shirasaki , Kosei Shiroyama
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