Publicação

Characterization of the Cross-covariance Functions through the Direct Covariances: Accepted October 2026

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Detalhes bibliográficos
Resumo:The current research aims to characterize the multivariate spatial dependency by expressing the cross-covariance functions in terms of the direct covariances, under second-order stationarity. This approach reduces the dimensionality of the estimation problem and enables a separate specification of the different components, thus avoiding a joint estimation of all the covariance functions. We derive bounds for the approximations errors and establish sufficient conditions to ensure the positive-definiteness of the resulting multivariate covariance structure. Theoretical properties of the proposed approximations are studied within a multivariate stochastic process framework. Implications for spatial inference and kriging-based prediction are discussed.
Autores principais:García-Soidán, Pilar
Outros Autores:Menezes, Raquel; Tinoco, Daniel; Pilar, García-Soidán
Assunto:covariance function covariate multivariate process positive-definiteness stationarity
Ano:2026
País:Portugal
Tipo de documento:artigo
Tipo de acesso:unknown
Instituição associada:Instituto Nacional de Estatística
Idioma:inglês
Origem:REVSTAT-Statistical Journal
Descrição
Resumo:The current research aims to characterize the multivariate spatial dependency by expressing the cross-covariance functions in terms of the direct covariances, under second-order stationarity. This approach reduces the dimensionality of the estimation problem and enables a separate specification of the different components, thus avoiding a joint estimation of all the covariance functions. We derive bounds for the approximations errors and establish sufficient conditions to ensure the positive-definiteness of the resulting multivariate covariance structure. Theoretical properties of the proposed approximations are studied within a multivariate stochastic process framework. Implications for spatial inference and kriging-based prediction are discussed.

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