Sparsity induced by covariance transformation: some deterministic and probabilistic results
File(s)skewSymmSparse20210126c.pdf (542.56 KB)
Accepted version
Author(s)
Rybak, Jakub
Battey, Heather
Type
Journal Article
Abstract
Motivated by statistical challenges arising in modern scientific fields, notably genomics, this paper seeks embeddings in which relevant covariance models are sparse. The work exploits a bijective mapping between a strictly positive definite matrix and its orthonormal eigen-decomposition, and between an orthonormal eigenvector matrix and its principle matrix logarithm. This leads to a representation of covariance matrices in terms of skew-symmetric matrices, for which there is a natural basis representation, and through which sparsity is conveniently explored. This theoretical work establishes the possibility of exploiting sparsity in the new parameterisation and converting the conclusion back to the one of interest, a prospect of high relevance in statistics. The statistical aspects associated with this operation, while not a focus of the present work, are briefly discussed.
Date Issued
2021-03-31
Date Acceptance
2021-02-03
Citation
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2021, 477 (2247)
ISSN
1364-5021
Publisher
The Royal Society
Journal / Book Title
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences
Volume
477
Issue
2247
Copyright Statement
© 2021 The Author(s) Published by the Royal Society. All rights reserved.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Engineering and Physical Sciences Research Council
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/P002757/1
EP/P002757/1
EP/T01864X/1
EP/T01864X/1
Subjects
01 Mathematical Sciences
02 Physical Sciences
09 Engineering
Publication Status
Published
Article Number
20200756
Date Publish Online
2021-03-03