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We analyse the efficiency of future large scale structure surveys to unveil the presence of scale dependent features in the primordial spectrum --resulting from cosmic inflation-- imprinted in the distribution of galaxies. Features may…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-04 Gonzalo A. Palma , Domenico Sapone , Spyros Sypsas

Much attention has been given to the problem of estimating cosmological parameters from the $C_l$ measured by future experiments. Many of the approaches which are being used either invoke poorly controlled approximations or are…

Astrophysics · Physics 2007-05-23 Benjamin D. Wandelt , Eric Hivon , Krzysztof M. Gorski

We implement EuclidEmulator (version 1), an emulator for the non-linear correction of the matter power spectrum, into the MCMC forecasting code MontePython. We compare the performance of Halofit, HMCode, and EuclidEmulator1, both at the…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 Mischa Knabenhans , Thejs Brinckmann , Joachim Stadel , Aurel Schneider , Romain Teyssier

We propose a new strategy to probe the power spectrum on large scales using galaxy peculiar velocities. We explore the properties of surveys that cover only two small fields in opposing directions on the sky. Surveys of this type have…

Astrophysics · Physics 2009-10-30 Hume A. Feldman , Richard Watkins

Weak gravitational lensing causes subtle changes in the apparent shapes of galaxies due to the bending of light by the gravity of foreground masses. By measuring the shapes of large numbers of galaxies (millions in recent surveys, up to…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-08 Yuki Okura , Andrea Petri , Morgan May , Andrés A. Plazas , Toru Tamagawa

Over the next decade, improvements in cosmological parameter constraints will be driven by surveys of large-scale structure. Its inherent non-linearity suggests that significant information will be embedded in higher correlations beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Joyce Byun , Alexander Eggemeier , Donough Regan , David Seery , Robert E. Smith

Computing the inverse covariance matrix (or precision matrix) of large data vectors is crucial in weak lensing (and multi-probe) analyses of the large scale structure of the universe. Analytically computed covariances are noise-free and…

Instrumentation and Methods for Astrophysics · Physics 2017-12-06 Oliver Friedrich , Tim Eifler

Magnification bias, an observational effect of gravitational lensing in the weak regime, allows testing the cosmological model through angular correlations of sources at different redshifts. This effect has been observed in various…

Measurements of the power spectrum from large-scale structure surveys have to date assumed an equal-time approximation, where the full cross-correlation power spectrum of the matter density field evaluated at different times (or distances)…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-05 T. D. Kitching , A. F. Heavens

Cosmic shear data contains a large amount of cosmological information encapsulated in the non-Gaussian features of the weak lensing mass maps. This information can be extracted using non-Gaussian statistics. We compare the constraining…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-20 Dominik Zürcher , Janis Fluri , Raphael Sgier , Tomasz Kacprzak , Alexandre Refregier

I discuss the use of cross correlations between galaxies with distance information and projected weak lensing dark matter maps to obtain a fully three dimensional dark matter map and power spectrum. On large scales l<100 one expects the…

Astrophysics · Physics 2009-11-10 Ue-Li Pen

We present a theoretical and exact analysis of the bispectrum of projected galaxy catalogues. The result can be generalized to evaluate the projection in spherical harmonics of any 3D bispectrum and therefore has applications to cosmic…

Astrophysics · Physics 2015-06-24 Licia Verde , Alan F. Heavens , Sabino Matarrese

Photometric galaxy surveys probe the late-time Universe where the density field is highly non-Gaussian. A consequence is the emergence of the super-sample covariance (SSC), a non-Gaussian covariance term that is sensitive to fluctuations on…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-23 S. Gouyou Beauchamps , F. Lacasa , I. Tutusaus , M. Aubert , P. Baratta , A. Gorce , Z. Sakr

In this paper we discuss the commonly-used limiting cases, or approximations, for two-point cosmic shear statistics. We discuss the most prominent assumptions in this statistic: the flat-sky (small angle limit), the Limber (Bessel-to-delta…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Thomas D. Kitching , Justin Alsing , Alan F. Heavens , Raul Jimenez , Jason D. McEwen , Licia Verde

We present two estimators to quantify the angular power spectrum of the sky signal directly from the visibilities measured in radio interferometric observations. This is relevant for both the foregrounds and the cosmological 21-cm signal…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-11 Samir Choudhuri , Somnath Bharadwaj , Abhik Ghosh , SK. Saiyad Ali

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

We revisit the flat-sky approximation for evaluating the angular power spectra of projected random fields by retaining information about the correlations along the line of sight. With broad, overlapping radial window functions, these…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-16 Zucheng Gao , Zvonimir Vlah , Anthony Challinor

Modern cosmological surveys are delivering datasets characterized by unprecedented quality and statistical completeness; this trend is expected to continue into the future as new ground- and space-based surveys come online. In order to…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-21 Kelly R. Moran , Katrin Heitmann , Earl Lawrence , Salman Habib , Derek Bingham , Amol Upadhye , Juliana Kwan , David Higdon , Richard Payne

We consider the bias introduced by a spatially-varying multiplicative shear bias (m-bias) on tomographic cosmic shear angular power spectra. To compute the bias in the power spectra, we estimate the mode-coupling matrix associated with an…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-30 Casey Cragg , Christopher A. J. Duncan , Lance Miller , David Alonso

An accurate theoretical template for the galaxy power spectrum is a key for the success of ongoing and future spectroscopic surveys. We examine to what extent the Effective Field Theory of Large Scale Structure is able to provide such a…