Algebraic extensions of semi-hyponormal operators

Authors
Kim, MK Ko, E
Citation
Mk. Kim et E. Ko, Algebraic extensions of semi-hyponormal operators, INTEG EQ OP, 37(4), 2000, pp. 449-456
Citations number
10
Categorie Soggetti
Mathematics
Journal title
INTEGRAL EQUATIONS AND OPERATOR THEORY
ISSN journal
0378620X → ACNP
Volume
37
Issue
4
Year of publication
2000
Pages
449 - 456
Database
ISI
SICI code
0378-620X(200008)37:4<449:AEOSO>2.0.ZU;2-G
Abstract
In this paper, we show that algebraic extensions of semi-hyponormal operato rs (defined below) are subscalar. As corollaries we get the following: (1) Every k-quasihyponormal operator is subscalar. (2) Every algebraic extension of Aluthge transforms of p-hyponormal operato rs is subscalar. From these results and [Es] it is known that such operators with 'rich spec tra' have nontrivial invariant subspaces.