Chi-Square Approximation for the Distribution of Individual Eigenvalues of a Singular Wishart Matrix

This paper discusses the approximate distributions of eigenvalues of a singular Wishart matrix. We give the approximate joint density of eigenvalues by Laplace approximation for the hypergeometric functions of matrix arguments. Furthermore, we show that the distribution of each eigenvalue can be app...

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Main Authors: Koki Shimizu, Hiroki Hashiguchi
Format: Article
Language:English
Published: MDPI AG 2024-03-01
Series:Mathematics
Subjects:
Online Access:https://www.mdpi.com/2227-7390/12/6/921
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author Koki Shimizu
Hiroki Hashiguchi
author_facet Koki Shimizu
Hiroki Hashiguchi
author_sort Koki Shimizu
collection DOAJ
description This paper discusses the approximate distributions of eigenvalues of a singular Wishart matrix. We give the approximate joint density of eigenvalues by Laplace approximation for the hypergeometric functions of matrix arguments. Furthermore, we show that the distribution of each eigenvalue can be approximated by the chi-square distribution with varying degrees of freedom when the population eigenvalues are infinitely dispersed. The derived result is applied to testing the equality of eigenvalues in two populations.
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spelling doaj.art-3c786a62233846fda3004f91bd62ecfc2024-03-27T13:53:19ZengMDPI AGMathematics2227-73902024-03-0112692110.3390/math12060921Chi-Square Approximation for the Distribution of Individual Eigenvalues of a Singular Wishart MatrixKoki Shimizu0Hiroki Hashiguchi1Department of Applied Mathematics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, JapanDepartment of Applied Mathematics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, JapanThis paper discusses the approximate distributions of eigenvalues of a singular Wishart matrix. We give the approximate joint density of eigenvalues by Laplace approximation for the hypergeometric functions of matrix arguments. Furthermore, we show that the distribution of each eigenvalue can be approximated by the chi-square distribution with varying degrees of freedom when the population eigenvalues are infinitely dispersed. The derived result is applied to testing the equality of eigenvalues in two populations.https://www.mdpi.com/2227-7390/12/6/921hypergeometric functionslaplace approximationspiked covariance model
spellingShingle Koki Shimizu
Hiroki Hashiguchi
Chi-Square Approximation for the Distribution of Individual Eigenvalues of a Singular Wishart Matrix
Mathematics
hypergeometric functions
laplace approximation
spiked covariance model
title Chi-Square Approximation for the Distribution of Individual Eigenvalues of a Singular Wishart Matrix
title_full Chi-Square Approximation for the Distribution of Individual Eigenvalues of a Singular Wishart Matrix
title_fullStr Chi-Square Approximation for the Distribution of Individual Eigenvalues of a Singular Wishart Matrix
title_full_unstemmed Chi-Square Approximation for the Distribution of Individual Eigenvalues of a Singular Wishart Matrix
title_short Chi-Square Approximation for the Distribution of Individual Eigenvalues of a Singular Wishart Matrix
title_sort chi square approximation for the distribution of individual eigenvalues of a singular wishart matrix
topic hypergeometric functions
laplace approximation
spiked covariance model
url https://www.mdpi.com/2227-7390/12/6/921
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