Heredity for triangular operators

Auteurs-es

  • Henry Crawford Rhaly Jr. retired from university teaching

DOI :

https://doi.org/10.5269/bspm.v31i2.17928

Mots-clés :

posinormal operator, dominant operator, compact operator, $M$-hyponormal operator, hyponormal operator, triangular matrix, terraced matrix

Résumé

A proof is given that if the lower triangular infinite matrix $T$ acts boundedly on $\ell^2$ and U is the unilateral shift, the sequence $(U^*)^nTU^n$ inherits from $T$ the following properties: posinormality, dominance, $M$-hyponormality, hyponormality, normality, compactness, and noncompactness.  Also, it is demonstrated that the upper triangular matrix $T^*$ is dominant if and only if $T$ is a diagonal matrix.

Biographie de l'auteur-e

  • Henry Crawford Rhaly Jr., retired from university teaching
    retired from university teaching

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Publié

2013-12-12

Numéro

Rubrique

Research Articles