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Related papers: Jackknife resampling technique on mocks: an altern…

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We describe the construction of an N-body simulation that mimics the true velocity and mass-density fields in a box of side 256\hmpc about the Local Group , and the production of mock catalogs that mimic in detail current catalogs of…

Astrophysics · Physics 2009-10-28 Tsafrir Kolatt , Avishai Dekel , Galit Ganon , Jeffrey Willick

This article is the second in a series in which we perform an extensive comparison of various galaxy-based cluster mass estimation techniques that utilise the positions, velocities and colours of galaxies. Our aim is to quantify the…

We train neural networks to quickly generate redshift-space galaxy power spectrum covariances from a given parameter set (cosmology and galaxy bias). This covariance emulator utilizes a combination of traditional fully-connected network…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-02 Joseph Adamo , Hung-Jin Huang , Tim Eifler

Modern statistical analysis often encounters datasets with large sizes. For these datasets, conventional estimation methods can hardly be used immediately because practitioners often suffer from limited computational resources. In most…

Methodology · Statistics 2023-04-14 Shuyuan Wu , Xuening Zhu , Hansheng Wang

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

The Canonical Polyadic (CP) tensor decomposition is frequently used as a model in applications in a variety of different fields. Using jackknife resampling to estimate parameter uncertainties is often desirable but results in an increase of…

Mathematical Software · Computer Science 2022-04-14 Christos Psarras , Lars Karlsson , Rasmus Bro , Paolo Bientinesi

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

We give an analytical interpretation of how subsample-based internal covariance estimators lead to biased estimates of the covariance, due to underestimating the super-sample covariance (SSC). This includes the jackknife and bootstrap…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-16 Fabien Lacasa , Martin Kunz

In many astrophysical settings covariance matrices of large datasets have to be determined empirically from a finite number of mock realisations. The resulting noise degrades inference and precludes it completely if there are fewer…

Instrumentation and Methods for Astrophysics · Physics 2017-01-11 Benjamin Joachimi

Covariance matrices are important tools for obtaining reliable parameter constraints. Advancements in cosmological surveys lead to larger data vectors and, consequently, increasingly complex covariance matrices, whose number of elements…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-31 Tassia Ferreira , Valerio Marra

We apply an iterative reconstruction method to galaxy mocks in redshift space obtained from $N$-body simulations. Comparing the two-point correlation functions for the reconstructed density field, we find that although the performance is…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-26 Ryuichiro Hada , Daniel J. Eisenstein

Relying on recent advances in statistical estimation of covariance distances based on random matrix theory, this article proposes an improved covariance and precision matrix estimation for a wide family of metrics. The method is shown to…

Machine Learning · Statistics 2021-02-03 Malik Tiomoko , Florent Bouchard , Guillaume Ginholac , Romain Couillet

Next-generation optical imaging surveys will revolutionise the observations of weak gravitational lensing by galaxy clusters and provide stringent constraints on growth of structure and cosmic acceleration. In these experiments, accurate…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-17 Hao-Yi Wu , David H. Weinberg , Andrés N. Salcedo , Benjamin D. Wibking , Ying Zu

This work proposes a method to accelerate the acquisition of high-quality edited magnetic resonance spectroscopy (MRS) scans using machine learning models taking the sample covariance matrix as input. The method is invariant to the number…

Weak lensing has become a powerful tool for probing the matter distribution in the Universe and constraining cosmological parameters. This paper aims to explore the fast mock generation pipeline to obtain the covariance matrix of the…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-17 Yiming Hu , Yu Yu

This article presents a new method to compute matrices from numerical simulations based on the ideas of sparse sampling and compressed sensing. The method is useful for problems where the determination of the entries of a matrix constitutes…

Chemical Physics · Physics 2014-10-21 Jacob N. Sanders , Xavier Andrade , Alán Aspuru-Guzik

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

We apply two compression methods to the galaxy power spectrum monopole/quadrupole and bispectrum monopole measurements from the BOSS DR12 CMASS sample. Both methods reduce the dimension of the original data-vector to the number of…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-07 Davide Gualdi , Héctor Gil-Marín , Robert L. Schuhmann , Marc Manera , Benjamin Joachimi , Ofer Lahav

We present a novel application of cosmological rescaling, or "remapping," to generate 21 cm intensity mapping mocks for different cosmologies. The remapping method allows for computationally efficient generation of N-body catalogs by…

The paper illustrates an application of the Resampling approach [2] for the estimation of the aircraft circulation plan reliability. Resampling is an intensive computer statistical method, which can be used effectively in the case of small…

Applications · Statistics 2013-05-14 Maxim Fioshin