Drazin-Moore-Penrose invertibility in rings

Characterizations are given for elements in an arbitrary ring with involution, having a group inverse and a Moore-Penrose inverse that are equal and the difference between these elements and EP-elements is explained. The results are also generalized to elements for which a power has a Moore-Penrose...

Full description

Bibliographic Details
Main Author: Patrício, Pedro (author)
Other Authors: Puystjens, Roland (author)
Format: article
Language:eng
Published: 2004
Subjects:
Online Access:http://hdl.handle.net/1822/1516
Country:Portugal
Oai:oai:repositorium.sdum.uminho.pt:1822/1516
Description
Summary:Characterizations are given for elements in an arbitrary ring with involution, having a group inverse and a Moore-Penrose inverse that are equal and the difference between these elements and EP-elements is explained. The results are also generalized to elements for which a power has a Moore-Penrose inverse and a group inverse that are equal. As an application we consider the ring of square matrices of order $m$ over a projective free ring $R$ with involution such that $R^m$ is a module of finite length, providing a new characterization for range-Hermitian matrices over the complexes.