English
Related papers

Related papers: A systematic approach to Covariance matrix formula…

200 papers

We study the covariance of the cross-power spectrum of different tracers for the large-scale structure. We develop the counts-in-cells framework for the multi-tracer approach, and use this to derive expressions for the full non-Gaussian…

Astrophysics · Physics 2015-05-13 Robert E. Smith

We evaluate the covariance matrix of the matter power spectrum using perturbation theory up to dominant terms at 1-loop order and compare it to numerical simulations. We decompose the covariance matrix into the disconnected (Gaussian) part,…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-18 Irshad Mohammed , Uros Seljak , Zvonimir Vlah

We consider estimation of covariance matrices and their inverses (a.k.a. precision matrices) for high-dimensional stationary and locally stationary time series. In the latter case the covariance matrices evolve smoothly in time, thus…

Statistics Theory · Mathematics 2014-01-07 Xiaohui Chen , Mengyu Xu , Wei Biao Wu

The major sources of abundant data are constantly expanding with the available data collection methodologies in various applications - medical, insurance, scientific, bio-informatics and business. These data sets may be distributed…

Distributed, Parallel, and Cluster Computing · Computer Science 2016-06-24 Aruna Govada , Sanjay K. Sahay

Estimation of the covariance matrix of asset returns is crucial to portfolio construction. As suggested by economic theories, the correlation structure among assets differs between emerging markets and developed countries. It is therefore…

Methodology · Statistics 2021-09-28 Xin Chen , Dan Yang , Yan Xu , Yin Xia , Dong Wang , Haipeng Shen

Extracting parameter constraints from cosmological observations requires accurate determination of the covariance matrix for use in the likelihood function. We show here that uncertainties in the elements of the covariance matrix propagate…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Scott Dodelson , Michael D. Schneider

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

Estimating large covariance and precision matrices are fundamental in modern multivariate analysis. The problems arise from statistical analysis of large panel economics and finance data. The covariance matrix reveals marginal correlations…

Methodology · Statistics 2015-04-17 Jianqing Fan , Yuan Liao , Han Liu

We study covariance matrix estimation for the case of partially observed random vectors, where different samples contain different subsets of vector coordinates. Each observation is the product of the variable of interest with a $0-1$…

Machine Learning · Statistics 2018-04-06 Eduardo Pavez , Antonio Ortega

We describe a statistical model to estimate the covariance matrix of matter tracer two-point correlation functions with cosmological simulations. Assuming a fixed number of cosmological simulation runs, we describe how to build a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Christopher B. Morrison , Michael D. Schneider

Parameter inference with an estimated covariance matrix systematically loses information due to the remaining uncertainty of the covariance matrix. Here, we quantify this loss of precision and develop a framework to hypothetically restore…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-16 Elena Sellentin , Alan F. Heavens

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.…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-30 Yongseok Jo , Shy Genel , Joel Leja , Benjamin Wandelt

We propose a general procedure for estimating the variance-covariance matrix of two-step estimates of structural parameters in latent variable models. The method is partially simulation-based, in that it includes drawing simulated values of…

Methodology · Statistics 2025-07-23 Roberto Di Mari , Jouni Kuha

Estimation of covariance matrices is a fundamental problem in multivariate statistics. Recently, growing efforts have focused on incorporating covariate effects into these matrices, facilitating subject-specific estimation. Despite these…

Methodology · Statistics 2026-04-10 Rakheon Kim , Emma Jingfei Zhang

We describe an approximate statistical model for the sample variance distribution of the non-linear matter power spectrum that can be calibrated from limited numbers of simulations. Our model retains the common assumption of a multivariate…

Covariance matrices of random vectors contain information that is crucial for modelling. Specific structures and patterns of the covariances (or correlations) may be used to justify parametric models, e.g., autoregressive models. Until now,…

Methodology · Statistics 2025-02-11 Paavo Sattler , Dennis Dobler

Approximating significance scans of searches for new particles in high-energy physics experiments as Gaussian fields is a well-established way to estimate the trials factors required to quantify global significances. We propose a novel,…

Data Analysis, Statistics and Probability · Physics 2023-10-23 V. Ananiev , A. L. Read

The spectrum and coherency are useful quantities for characterizing the temporal correlations and functional relations within and between point processes. This paper begins with a review of these quantities, their interpretation and how…

Biological Physics · Physics 2007-05-23 M. R. Jarvis , P. P. Mitra

Data analysis in cosmology requires reliable covariance matrices. Covariance matrices derived from numerical simulations often require a very large number of realizations to be accurate. When a theoretical model for the covariance matrix…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-21 Alessandra Fumagalli , Matteo Biagetti , Alexandro Saro , Emiliano Sefusatti , Anže Slosar , Pierluigi Monaco , Alfonso Veropalumbo

The covariance matrix plays a fundamental role in many modern exploratory and inferential statistical procedures, including dimensionality reduction, hypothesis testing, and regression. In low-dimensional regimes, where the number of…

Methodology · Statistics 2024-11-12 Philippe Boileau , Nima S. Hejazi , Mark J. van der Laan , Sandrine Dudoit