24 citations · 80 across the 39 of their papers we have counts for
6 papers · 1 filter
When is a CPD weighted shift similar to a subnormal operator?
Zenon Jan Jabłoński, Il Bong Jung, Jan Stochel
We prove that a CPD unilateral weighted shift of type III is a quasi-affine transform of the operator of multiplication by the independent variable on the -clos…
Hyperrigidity II: -dilations, ideals and decompositions
Paweł Pietrzycki, Jan Stochel
We investigate the hyperrigidity of subsets of unital -algebras annihilated by states (or, more generally, by completely positive maps). This is closely related to the concept…
Bishop-like theorems for non-subnormal operators
Zenon Jan Jabłoński, Il Bong Jung, Jan Stochel
The celebrated Bishop theorem states that an operator is subnormal if and only if it is the strong limit of a net (or a sequence) of normal operators. By the Agler-Stankus theorem,…
Hyperrigidity I: singly generated commutative -algebras
Paweł Pietrzycki, Jan Stochel
Although Arveson's hyperrigidity conjecture was recently resolved negatively by B. Bilich and A. Dor-On, the problem remains open for commutative -algebras. Relatively few exa…
Convergence of power sequences of operators via their stability
Zenon Jan Jabłoński, Il Bong Jung, Carlos Kubrusly +1
This paper is concerned with the convergence of power sequences and stability of Hilbert space operators, where "convergence" and "stability" refer to weak, strong and norm topolog…
Criteria for algebraic operators to be unitary
Zenon Jan Jablonski, Il Bong Jung, Jan Stochel
Criteria for an algebraic operator on a complex Hilbert space to be unitary are established. The main one is written in terms of the convergence of sequences of t…