The J-numerical range of a J-Hermitian matrix and related inequalities

• Autor(es): Nakazato, Hiroshi ; Bebiano, Natália ; Providência, João da
• Data: 2008
• Identificador Persistente: http://hdl.handle.net/10316/4585
• Origem: Estudo Geral - Universidade de Coimbra
• Assunto(s): Krein space; J-numerical range; J-Hermitian matrix
• Tipo de Documento: Artigo
• Idioma: Inglês

Descrição

Recently, indefinite versions of classical inequalities of Schur, Ky Fan and Rayleigh-Ritz on Hermitian matrices have been obtained for J-Hermitian matrices that are J-unitarily diagonalizable, J=Ir[circle plus operator](-Is),r,s>0. The inequalities were obtained in the context of the theory of numerical ranges of operators on indefinite inner product spaces. In this paper, the subject is revisited, relaxing the constraint of the matrices being J-unitarily diagonalizable. http://www.sciencedirect.com/science/article/B6V0R-4S0PX90-8/1/064ad8a9cee017320ee6aefd3de429a5