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Related papers: Disconnected pseudo-$C_\ell$ covariances for proje…

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An accurate covariance matrix is essential for obtaining reliable cosmological results when using a Gaussian likelihood. In this paper we study the covariance of pseudo-$C_\ell$ estimates of tomographic cosmic shear power spectra. Using two…

The covariance matrix of the matter power spectrum is a key element of the statistical analysis of galaxy clustering data. Independent realisations of observational measurements can be used to sample the covariance, nevertheless statistical…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-14 Linda Blot , Pier Stefano Corasaniti , Luca Amendola , Thomas D. Kitching

Likelihood fitting to two-point clustering statistics made from galaxy surveys usually assumes a multivariate normal distribution for the measurements, with justification based on the central limit theorem given the large number of…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-23 Mike Shengbo Wang , Will J. Percival , Santiago Avila , Robert Crittenden , Davide Bianchi

Weak gravitational lensing is one of the most promising tools to investigate the equation-of-state of dark energy. In order to obtain reliable parameter estimations for current and future experiments, a good theoretical understanding of…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-07 J. Pielorz , J. Rödiger , I. Tereno , P. Schneider

Optimal analyses using the 2-point functions of large-scale structure probes require accurate covariance matrices. A covariance matrix of the 2-point function comprises the disconnected part and the connected part. While the connected…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-14 Yin Li , Sukhdeep Singh , Byeonghee Yu , Yu Feng , Uros Seljak

We present the exact joint likelihood of pseudo-$C_\ell$ power spectrum estimates measured from an arbitrary number of Gaussian cosmological fields. Our method is applicable to both spin-0 fields and spin-2 fields, including a mixture of…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-09 Robin E. Upham , Lee Whittaker , Michael L. Brown

We study how well the Gaussian approximation is valid for computing the covariance matrices of the convergence power and bispectrum in weak gravitational lensing analyses. We focus on its impact on the cosmological parameter estimations by…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Masanori Sato , Takahiro Nishimichi

We investigate, in dark matter and galaxy mocks, the effects of approximating the galaxy power spectrum-bispectrum estimated covariance as a diagonal matrix, for an analysis that aligns with the specifications of recent and upcoming galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-12 Sergi Novell-Masot , Héctor Gil-Marín , Licia Verde

We perform a detailed analysis of the covariance matrix of the spherically averaged galaxy power spectrum and present a new, practical method for estimating this within an arbitrary survey without the need for running mock galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-18 Cullan Howlett , Will J. Percival

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 study the covariance of the cross-power spectrum of different tracers for the large-scale structure. We develop the counts-in-cells framework for the multi-tracer approach, and use this to derive expressions for the full non-Gaussian…

Astrophysics · Physics 2015-05-13 Robert E. Smith

We use analytic covariance matrices to carry out a full-shape analysis of the galaxy power spectrum multipoles from the Baryon Oscillation Spectroscopic Survey (BOSS). We obtain parameter estimates that agree well with those based on the…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-29 Digvijay Wadekar , Mikhail M. Ivanov , Roman Scoccimarro

Super sample covariance (SSC) is important when estimating covariance matrices using a set of mock catalogues for galaxy surveys. If the underlying cosmological simulations do not include the variation in background parameters appropriate…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-05 Greg Schreiner , Alex Krolewski , Shahab Joudaki , Will J. Percival

In recent years cosmic shear, the weak gravitational lensing effect by the large-scale structure of the Universe, has proven to be one of the observational pillars on which the cosmological concordance model is founded. Several cosmic shear…

Astrophysics · Physics 2008-03-12 B. Joachimi , P. Schneider , T. Eifler

We address the amount of information in the non-Gaussian regime of weak lensing surveys by modelling all relevant covariances of the power spectra and bispectra, using 1000 ray-tracing simulation realizations for a Lambda-CDM model and an…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-09 Issha Kayo , Masahiro Takada , Bhuvnesh Jain

Gravitational clustering is an intrinsically non-linear process that generates significant non-Gaussian signatures in the density field. We consider how these affect power spectrum determinations from galaxy and weak-lensing surveys.…

Astrophysics · Physics 2008-11-26 Roman Scoccimarro , Matias Zaldarriaga , Lam Hui

We present a study on the robustness of the covariance matrix estimation for galaxy clustering measurements depending on the cosmological parameters and galaxy bias. To this end, we have produced 9000 galaxy mock catalogues relying on the…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 Falk Baumgarten , Chia-Hsun Chuang

The abundance of clusters and the clustering of galaxies are two of the important cosmological probes for current and future large scale surveys of galaxies, such as the Dark Energy Survey. In order to combine them one has to account for…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-17 Fabien Lacasa , Rogerio Rosenfeld

Making cosmological inferences from the observed galaxy clustering requires accurate predictions for the mean clustering statistics and their covariances. Those are affected by cosmic variance -- the statistical noise due to the finite…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Anatoly Klypin , Francisco Prada , Joyce Byun

(Abridged) Combining cosmic shear power spectra and cluster counts is powerful to improve cosmological parameter constraints and/or test inherent systematics. However they probe the same cosmic mass density field, if the two are drawn from…

Astrophysics · Physics 2009-06-23 Masahiro Takada , Sarah Bridle
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