J. Stochel

activity

20092026

most citedOn Unbounded Composition Operators in

L^{2}

-Spaces

24 citations · 80 across the 39 of their papers we have counts for

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2 papers · 1 filter

math.FA2026

Solutions to the 'moment property implies subnormality' and injectivity problems for composition operators on one-circuit graphs

Piotr Budzyński, Zenon Jan Jabłoński, Il Bong Jung +1

We consider composition operators in $L^{2} (μ)$ , where $μ$ is a discrete measure. Our main result shows that, for every integer $p \geq 2$ , there exists a non-hyponormal composition ope…

math.FA2026

CPD $n$ th roots of subnormal operators are subnormal

Zenon Jan Jabłoński, Il Bong Jung, Paweł Pietrzycki +1

We investigate the $n$ th root problem for bounded operators on a Hilbert space within the class of conditionally positive definite (CPD) operators determined by the Lévy--Khintchin…

Solutions to the 'moment property implies subnormality' and injectivity problems for composition operators on one-circuit graphs

CPD nth roots of subnormal operators are subnormal

CPD $n$ th roots of subnormal operators are subnormal