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It is known that modeling uncertainties and astrophysical foregrounds can potentially introduce appreciable bias in the deduced values of cosmological parameters. While it is commonly assumed that these uncertainties will be accounted for…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Meir Shimon , Nissan Itzhaki , Yoel Rephaeli

Poisson distributed shot noise is normally considered in the Gaussian limit in cosmology. However, if the shot noise is large enough and the correlation function/power spectrum conspires, the Gaussian approximation mis-estimates the errors…

Astrophysics · Physics 2009-01-23 J. D. Cohn

Upcoming large redshift surveys potentially allow precision measurements of the galaxy power spectrum. To accurately measure P(k) on the largest scales, comparable to the depth of the survey, it is crucial that finite volume effects are…

Astrophysics · Physics 2016-01-27 Max Tegmark

Measurement of Cosmic Microwave Background (CMB) anisotropies has been playing a lead role in precision cosmology by providing some of the tightest constrains on cosmological models and parameters. However, precision can only be meaningful…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-16 Santanu Das , Sanjit Mitra , Sonu Tabitha Paulson

It is usually assumed that the ellipticity power spectrum measured in weak lensing observations can be expressed as an integral over the underlying matter power spectrum. This is true at second order in the gravitational potential. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Elisabeth Krause , Christopher M. Hirata

A large fraction of the information collected by cosmological surveys is simply discarded to avoid lengthscales which are difficult to model theoretically. We introduce a new technique which enables the extraction of useful information from…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-08 Fergus Simpson , J. Berian James , Alan F. Heavens , Catherine Heymans

Several cosmological measurements have attained significant levels of maturity and accuracy over the last decade. Continuing this trend, future observations promise measurements of the statistics of the cosmic mass distribution at an…

Astrophysics · Physics 2008-11-26 Salman Habib , Katrin Heitmann , David Higdon , Charles Nakhleh , Brian Williams

Super-sample covariance (SSC) is an important effect for cosmological analyses that use the deep structure of the cosmic web; it may, however, be nontrivial to include it practically in a pipeline. We solve this difficulty by presenting a…

Future galaxy surveys hope to realize significantly tighter constraints on various cosmological parameters. The higher number densities achieved by these surveys will allow them to probe the smaller scales affected by non-linear clustering.…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-17 Andrew Repp , István Szapudi

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

The observable universe contains density perturbations on scales larger than any finite volume survey. Perturbations on scales larger than a survey can measure degrade its power to constrain cosmological parameters. The dependence of survey…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-09 Matthew C. Digman , Joseph E. McEwen , Christopher M. Hirata

Weak gravitational lensing is becoming a mature technique for constraining cosmological parameters, and future surveys will be able to constrain the dark energy equation of state $w$. When analyzing galaxy surveys, redshift information has…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-07 Andrea Petri , Morgan May , Zoltán Haiman

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

The advent of Stage IV weak lensing surveys will open up a new era in precision cosmology. These experiments will offer more than an order-of-magnitude leap in precision over existing surveys, and we must ensure that the accuracy of our…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-09 Anurag C. Deshpande , Thomas D. Kitching

Uncertainties in predicting the nonlinear clustering of matter are among the most serious theoretical systematics facing the upcoming wide-field weak gravitational lensing surveys. We estimate the accuracy with which the matter power…

Astrophysics · Physics 2011-05-12 Dragan Huterer , Masahiro Takada

We modified the CLASS code in order to include relativistic galaxy number counts in spatially curved geometries; we present the formalism and study the effect of relativistic corrections on spatial curvature. The new version of the code is…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-08 Enea Di Dio , Francesco Montanari , Alvise Raccanelli , Ruth Durrer , Marc Kamionkowski , Julien Lesgourgues

Following on our purpose of developing a unified pipeline for large-scale structure data analysis with angular (i.e. harmonic-space) power spectra, we now include the weak lensing effect of magnification bias on galaxy clustering in a…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-28 Konstantinos Tanidis , Stefano Camera , David Parkinson

The primary science driver for 3D galaxy surveys is their potential to constrain cosmological parameters. Forecasts of these surveys' effectiveness typically assume Gaussian statistics for the underlying matter density, despite the fact…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-27 Andrew Repp , István Szapudi , Julien Carron , Melody Wolk

We review the effect of the commonly-used Limber and flat-sky approximations on the calculation of shear power spectra and correlation functions for galaxy weak lensing. These approximations are accurate at small scales, but it has been…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-17 Pablo Lemos , Anthony Challinor , George Efstathiou

This paper focuses on two aspects of the statistics of cosmological observables that are important for the next stages of precision cosmology. First, we note that the theory of reduced angular $N$-point spectra has only been developed in…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-02 Ermis Mitsou , Jaiyul Yoo , Ruth Durrer , Fulvio Scaccabarozzi , Vittorio Tansella