On Elliptical and Inverse Elliptical Wishart distributions

Fuente: arXiv
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Auteurs principaux: Ayadi, Imen, Bouchard, Florent, Pascal, Frédéric
Format: Preprint
Publié: 2024
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author Ayadi, Imen
Bouchard, Florent
Pascal, Frédéric
author_facet Ayadi, Imen
Bouchard, Florent
Pascal, Frédéric
contents This paper deals with the Elliptical Wishart and Inverse Elliptical Wishart distributions, which play a major role when handling covariance matrices. Similarly to multivariate elliptical distributions, these form a large family of covariance distributions, encompassing, e.g., the Wishart or \textit{t}-Wishart ones. Our first major contribution is to derive a stochastic representation for Elliptical Wishart and Inverse Elliptical Wishart matrices. This later enables us to obtain various key statistical properties of Elliptical Wishart and Inverse Elliptical Wishart distributions such as expectations, variances, and Kronecker moments up to any orders. The stochastic representation also allows us to provide an efficient method to generate random matrices from Elliptical Wishart and Inverse Elliptical Wishart distributions. Finally, the practical interest of Elliptical Wishart distributions - in particular the \textit{t}-Wishart one - is demonstrated through a fitting experiment on real electroencephalographic data. This showcases their effectiveness in accurately modeling real covariance matrices.
format Preprint
id arxiv_https___arxiv_org_abs_2404_17468
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On Elliptical and Inverse Elliptical Wishart distributions
Ayadi, Imen
Bouchard, Florent
Pascal, Frédéric
Statistics Theory
Methodology
This paper deals with the Elliptical Wishart and Inverse Elliptical Wishart distributions, which play a major role when handling covariance matrices. Similarly to multivariate elliptical distributions, these form a large family of covariance distributions, encompassing, e.g., the Wishart or \textit{t}-Wishart ones. Our first major contribution is to derive a stochastic representation for Elliptical Wishart and Inverse Elliptical Wishart matrices. This later enables us to obtain various key statistical properties of Elliptical Wishart and Inverse Elliptical Wishart distributions such as expectations, variances, and Kronecker moments up to any orders. The stochastic representation also allows us to provide an efficient method to generate random matrices from Elliptical Wishart and Inverse Elliptical Wishart distributions. Finally, the practical interest of Elliptical Wishart distributions - in particular the \textit{t}-Wishart one - is demonstrated through a fitting experiment on real electroencephalographic data. This showcases their effectiveness in accurately modeling real covariance matrices.
title On Elliptical and Inverse Elliptical Wishart distributions
topic Statistics Theory
Methodology
url https://arxiv.org/abs/2404.17468