On a weighted Toeplitz operator and its commutant.
Some remarks on the invariant subspace problem for hyponormal operators.
Some estimates of certain subnormal and hyponormal derivations.
A note on the range of the operator defined on .
A Fuglede-Putnam theorem modulo the Hilbert-Schmidt class for almost normal operators with finite modulus of Hilbert-Schmidt quasi-triangularity
We extend the Fuglede-Putnam theorem modulo the Hilbert-Schmidt class to almost normal operators with finite Hilbert-Schmidt modulus of quasi-triangularity.
A remark concerning Putinar's model of hyponormal weighted shifts
The question whether a hyponormal weighted shift with trace class self-commutator is the compression modulo the Hilbert-Schmidt class of a normal operator, remains open. It is natural to ask whether Putinar's construction through which he proved that hyponormal operators are subscalar operators provides the answer to the above question. We show that the normal extension provided by Putinar's theory does not lead to the extension that would provide a positive answer to the question.
On a Kleinecke-Shirokov theorem
We prove that for normal operators the generalized commutator approaches zero when tends to zero in the norm of the Schatten-von Neumann class with and varies in a bounded set of such a class.
Page 1