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相关论文: The Effect of Covariance Estimator Error on Cosmol…

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Current and forthcoming cosmological data analyses share the challenge of huge datasets alongside increasingly tight requirements on the precision and accuracy of extracted cosmological parameters. The community is becoming increasingly…

天体物理仪器与方法 · 物理学 2014-12-17 Benjamin Joachimi , Andy Taylor

In cosmic shear likelihood analyses the covariance is most commonly assumed to be constant in parameter space. Therefore, when calculating the covariance matrix (analytically or from simulations), its underlying cosmology should not…

天体物理学 · 物理学 2015-05-13 Tim Eifler , Peter Schneider , Jan Hartlap

Cosmological large-scale structure analyses based on two-point correlation functions often assume a Gaussian likelihood function with a fixed covariance matrix. We study the impact on cosmological parameter estimation of ignoring the…

宇宙学与河外天体物理 · 物理学 2019-03-21 Darsh Kodwani , David Alonso , Pedro Ferreira

In this study, we investigate the impact of covariance within uncertainties on the inference of cosmological and astrophysical parameters, specifically focusing on galaxy stellar mass functions derived from the CAMELS simulation suite.…

宇宙学与河外天体物理 · 物理学 2024-10-30 Yongseok Jo , Shy Genel , Joel Leja , Benjamin Wandelt

Data analysis from upcoming large galaxy redshift surveys, such as Euclid and DESI will significantly improve constraints on cosmological parameters. To optimally extract the information from these galaxy surveys, it is important to control…

宇宙学与河外天体物理 · 物理学 2025-01-22 S. Gouyou Beauchamps , P. Baratta , S. Escoffier , W. Gillard , J. Bel , J. Bautista , C. Carbone

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…

宇宙学与河外天体物理 · 物理学 2016-04-14 Linda Blot , Pier Stefano Corasaniti , Luca Amendola , Thomas D. Kitching

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…

宇宙学与河外天体物理 · 物理学 2015-06-12 Andy Taylor , Benjamin Joachimi , Thomas Kitching

Focusing on the well motivated aperture mass statistics $\Map$, we study the possibility of constraining cosmological parameters using future space based SNAP class weak lensing missions. Using completely analytical results we construct the…

天体物理学 · 物理学 2007-05-23 Dipak Munshi , Patrick Valageas

The likelihood function for cosmological parameters, given by e.g. weak lensing shear measurements, depends on contributions to the covariance induced by the nonlinear evolution of the cosmic web. As nonlinear clustering to date has only…

宇宙学与河外天体物理 · 物理学 2019-02-26 Robert Reischke , Alina Kiessling , Björn Malte Schäfer

We investigate the bias and error in estimates of the cosmological parameter covariance matrix, due to sampling or modelling the data covariance matrix, for likelihood width and peak scatter estimators. We show that these estimators do not…

宇宙学与河外天体物理 · 物理学 2015-06-18 Andy Taylor , Benjamin Joachimi

Empirical estimates of the band power covariance matrix are commonly used in cosmic microwave background (CMB) power spectrum analyses. While this approach easily captures correlations in the data, noise in the resulting covariance estimate…

宇宙学与河外天体物理 · 物理学 2022-03-14 L. Balkenhol , C. L. Reichardt

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…

天体物理仪器与方法 · 物理学 2017-12-06 Oliver Friedrich , Tim Eifler

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…

宇宙学与河外天体物理 · 物理学 2022-05-31 Tassia Ferreira , Valerio Marra

Cosmological observables rely heavily on summary statistics such as two-point correlation functions. In many practical cases (e.g. the weak-lensing cosmic shear), those correlation functions are estimated from a finite, discrete sample of…

宇宙学与河外天体物理 · 物理学 2025-06-24 Pierre Fleury

We investigate simulation-based bandpower covariance matrices commonly used in cosmological parameter inferences such as the estimation of the tensor-to-scalar ratio $r$. We find that upper limits on $r$ can be biased low by tens of…

宇宙学与河外天体物理 · 物理学 2022-07-06 Dominic Beck , Ari Cukierman , W. L. Kimmy Wu

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…

宇宙学与河外天体物理 · 物理学 2015-06-12 Meir Shimon , Nissan Itzhaki , Yoel Rephaeli

Cosmological parameter estimation from forthcoming experiments promise to reach much greater precision than current constraints. As statistical errors shrink, the required control over systematic errors increases. Therefore, models or…

宇宙学与河外天体物理 · 物理学 2020-10-07 José Luis Bernal , Nicola Bellomo , Alvise Raccanelli , Licia Verde

We provide an efficient method to approximate the covariance between decision variables and uncertain parameters in solutions to a general class of stochastic nonlinear complementarity problems. We also develop a sensitivity metric to…

最优化与控制 · 数学 2018-10-10 Sriram Sankaranarayanan , Felipe Feijoo , Sauleh Siddiqui

Covariance matrices are essential cosmological probes of fundamental physics, providing information on numerous fundamental physical parameters and varying with any change in the underlying cosmology. However, this cosmology dependence,…

宇宙学与河外天体物理 · 物理学 2026-01-21 Theodore Steele , Robert Smith , Roisin O'Connor

We study the impact of cosmological parameters' uncertainties on estimates of the primordial NG parameter f_NL in local and equilateral models of non-Gaussianity. We show that propagating these errors increases the f_NL relative uncertainty…

天体物理学 · 物理学 2008-12-30 M. Liguori , A. Riotto
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