Solving an open problem about the G-Drazin partial order

G-Drazin inverses and the G-Drazin partial order for square matrices have been both recently introduced by Wang and Liu. They proved the following implication: If A is below B under the G-Drazin partial order, then any G-Drazin inverse of B is also a G-Drazin inverse of A. However, this necessary co...

ver descrição completa

Detalhes bibliográficos
Autores: Ferreyra, David Eduardo, Lattanzi, Marina Beatriz, Levis, Fabián Eduardo, Thome, Néstor
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2020
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositório:CONICET Digital (CONICET)
Idioma:inglês
OAI Identifier:oai:ri.conicet.gov.ar:11336/132022
Acesso em linha:http://hdl.handle.net/11336/132022
Access Level:Acceso aberto
Palavra-chave:G-DRAZIN INVERSE
G-DRAZIN PARTIAL ORDER
MINUS PARTIAL ORDER
SPACE PRE-ORDER
https://purl.org/becyt/ford/1.1
https://purl.org/becyt/ford/1
Descrição
Resumo:G-Drazin inverses and the G-Drazin partial order for square matrices have been both recently introduced by Wang and Liu. They proved the following implication: If A is below B under the G-Drazin partial order, then any G-Drazin inverse of B is also a G-Drazin inverse of A. However, this necessary condition could not be stated as a characterization and the validity (or not) of the converse implication was posed as an open problem. In this paper, this problem is completely solved. It is obtained that the converse, in general, is false, and a form to construct counterexamples is provided. It is also proved that the converse holds under an additional condition (which is also necessary) as well as for some special cases of matrices.