8 citations · 15 across the 8 of their papers we have counts for
9 papers · 1 filter
Conditionally positive definite unilateral weighted shifts
Zenon Jan Jabłoński, Il Bong Jung, Eun Young Lee +1
In a recent paper [15], Hilbert space operators with the property that each sequence of the form is conditionally positive definite in a semigr…
Taylor spectrum approach to Brownian-type operators with quasinormal entry
Sameer Chavan, Zenon Jan Jabłoński, Il Bong Jung +1
In this paper, we introduce operators that are represented by upper triangular block matrices whose entries satisfy some algebraic constraints. We call them Brownian-ty…
m-isometric operators and their local properties
Z. J. Jablonski, I. B. Jung, J. Stochel
In this paper we give necessary and sufficient conditions for a bounded linear Hilbert space operator to be an -isometry for an unspecified written in terms of conditions th…
A Subnormal Completion Problem for Weighted Shifts on Directed Trees, II
George R. Exner, Il Bong Jung, Jan Stochel +1
The subnormal completion problem on a directed tree is to determine, given a collection of weights on a subtree, whether the weights may be completed to the weights of a subnormal…
Almost invariant half-spaces for operators on Hilbert space. II: operator matrices
Il Bong Jung, Eungil Ko, Carl Pearcy
This paper is a sequel to [6]. In that paper we transferred the discussions in [1] and [13] concerning almost invariant half-spaces for operators on complex Banach spaces to the co…
Subnormality of unbounded composition operators over one-circuit directed graphs: exotic examples
Piotr Budzynski, Zenon Jan Jablonski, Il Bong Jung +1
A recent example of a non-hyponormal injective composition operator in an -space generating Stieltjes moment sequences, invented by three of the present authors, was built ove…