3 papers
math.FA2024
Bishop-like theorems for non-subnormal operators
Zenon Jan JabÅoÅski, 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,…
math.FA2024
Convergence of power sequences of operators via their stability
Zenon Jan JabÅoÅski, 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…
math.FA2024
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…