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Modeling the large-scale structure of the universe on nonlinear scales has the potential to substantially increase the science return of upcoming surveys by increasing the number of modes available for model comparisons. One way to achieve…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-30 Marcel Schmittfull , Zvonimir Vlah

The two-point summary statistics is one of the most commonly used tools in the study of cosmological structure. Starting from the theoretical power spectrum defined in the 3D volume and obtained via the process of ensemble averaging, we…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-02 Alvise Raccanelli , Zvonimir Vlah

Combination of the power spectrum and bispectrum is a powerful way of breaking degeneracies between galaxy bias and cosmological parameters, enabling us to maximize the constraining power from galaxy surveys. Recent cosmological constraints…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-21 Alexander Eggemeier , Roman Scoccimarro , Robert E. Smith

This paper presents a novel power spectral density estimation technique for band-limited, wide-sense stationary signals from sub-Nyquist sampled data. The technique employs multi-coset sampling and incorporates the advantages of compressed…

Information Theory · Computer Science 2012-05-18 Michael A. Lexa , Mike E. Davies , John S. Thompson

In order to best improve constraints on cosmological parameters and on models of modified gravity using current and future galaxy surveys it is necessary maximally exploit the available data. As redshift-space distortions mean statistical…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Donough Regan

A known problem in cosmic shear two-point statistics is the apparent inconsistency between analyses performed in harmonic space (power spectrum) and real space (angular correlation). This arises mainly from two factors: first, scale cuts in…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-20 João Ferri , Elisa G. M. Ferreira , Ryo Terasawa

We present an algorithm for quickly generating multiple realizations of N-body simulations to be used, for example, for cosmological parameter estimation from surveys of large-scale structure. Our algorithm uses a new method to resample the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Michael D. Schneider , Shaun Cole , Carlos S. Frenk , Istvan Szapudi

This is the second of two papers which address the problem of measuring the unredshifted power spectrum of fluctuations from a galaxy survey in optimal fashion. A key quantity is the Fisher matrix, which is the inverse of the covariance…

Astrophysics · Physics 2015-06-24 A. J. S. Hamilton

The non-Gaussian part of the covariance matrix of the galaxy power spectrum involves the connected four-point correlation in Fourier space, i.e. trispectrum. This paper introduces a fast method to compute the non-Gaussian part of the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-07 Yosuke Kobayashi

The void power spectrum is related to the clustering of low-density regions in the large-scale structure (LSS) of the Universe, and can be used as an effective cosmological probe to extract the information of the LSS. We generate the galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-01 Yingxiao Song , Qi Xiong , Yan Gong , Furen Deng , Kwan Chuen Chan , Xuelei Chen , Qi Guo , Guoliang Li , Ming Li , Yun Liu , Yu Luo , Wenxiang Pei , Chengliang Wei

We present a joint likelihood analysis of the real-space power spectrum and bispectrum measured from a variety of halo and galaxy mock catalogs. A novel aspect of this work is the inclusion of nonlinear triangle configurations for the…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-07 Alexander Eggemeier , Román Scoccimarro , Robert E. Smith , Martin Crocce , Andrea Pezzotta , Ariel G. Sánchez

We develop a method to estimate the power spectrum of a stochastic process on the sphere from data of limited geographical coverage. Our approach can be interpreted either as estimating the global power spectrum of a stationary process when…

Instrumentation and Methods for Astrophysics · Physics 2013-06-17 Mark A. Wieczorek , Frederik J. Simons

Redshift-space distortions in galaxy surveys happen along the radial direction, breaking statistical translation invariance. We construct estimators for radial distortions that, using only Fast Fourier Transforms (FFTs) of the overdensity…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Roman Scoccimarro

The three-dimensional galaxy power spectrum is a powerful probe of primordial non-Gaussianity and additional general relativistic (GR) effects on large scales, which can be constrained by the current and upcoming large-scale structure…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-03 Robin Y. Wen , Henry S. Grasshorn Gebhardt , Chen Heinrich , Olivier Doré

We examine the effect of a threshold bias on the power spectrum and the bispectrum in an ensemble of numerical simulations (Gaussian initial perturbations with power law spectra P(k) \sim k^n, n=+1, 0, -1, -2) and compare our results with…

Astrophysics · Physics 2015-06-24 J. N. Fry , Adrian L. Melott , Sergei F. Shandarin

The power spectrum estimated from a galaxy redshift survey is the real spectrum convolved with a window function, so when estimating the power on very large scales (for small k), it is important that this window function be as narrow as…

Astrophysics · Physics 2009-10-07 Max Tegmark

We investigate the use of estimators of weak lensing power spectra based on a flat-sky implementation of the Pseudo-Cl (PCl) technique, where the masked shear field is transformed without regard for masked regions of sky. This masking mixes…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-11 Marika Asgari , Andy Taylor , Benjamin Joachimi , Thomas D. Kitching

By measuring, modeling and interpreting cosmological datasets, one can place strong constraints on models of the Universe. Central to this effort are summary statistics such as power spectra and bispectra, which condense the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-15 Oliver H. E. Philcox , Thomas Flöss

Power spectrum estimation is an important tool in many applications, such as the whitening of noise. The popular multitaper method enjoys significant success, but fails for short signals with few samples. We propose a statistical model…

Statistics Theory · Mathematics 2018-12-10 Joakim Andén , Amit Singer

We present a unified approach to the problems of reconstruction of large-scale structure distribution in the universe and determination of the underlying power spectrum. These have often been treated as two separate problems and different…

Astrophysics · Physics 2009-10-30 Uros Seljak