6 papers
Structural Properties and Normality Criteria for Subclasses of Normaloid Operators
Hranislav StankoviÄ, Carlos Kubrusly
We investigate structural properties and normality criteria for certain classes of bounded linear operators on a Hilbert space. We show that an operator with polar decompositio…
Weak Quasistability and Rajchman measures
Carlos Kubrusly
It is shown that weak quasistability does not imply power boundedness, but coercive power unbounded operators cannot be weakly quasistable.\ Although a finite measure over the unit…
Weak Stability and Quasistability
C. S. Kubrusly, P. C. M. Vieira
It is known that weak l-sequential supercyclicity implies weak quasistability, and it is still unknown weather weak l-sequential supercyclicity implies weak stability, much less wh…
Forms of biisometric operators and biorthogonality
B. P. Duggal, C. S. Kubrusly
The paper proves two results involving a pair (A,B) of P-biisometric or (m,P)-biisometric Hilbert-space operators for arbitrary positive integer m and positive operator P. It is sh…
Weak Supercyclicity -- An Expository Survey
Carlos S. Kubrusly
This is an exposition on supercyclicity and weak supercyclicity, especially designed to advance further developments in weakly supercyclicity, which is a recent research field show…
Weak l-sequential supercyclicity and weak quasistability
C. S. Kubrusly, B. P. Duggal
It is known that supercyclicity implies strong stability. It is not known whether weak l-sequential supercyclicity implies weak stability. In this paper we prove that weak l-sequen…