Sous-normalité jointe non bornée et applications
Tom 171 / 2005
Studia Mathematica 171 (2005), 227-237 MSC: 47B20, 47A57, 47B15. DOI: 10.4064/sm171-3-2
T. Trent gave a new characterization of subnormality for an operator on a Hilbert space. T. Bînzar and D. Păunescu generalized this condition to commuting triples of operators. Here, we give an $n$-variable unbounded version of the above results. Theorems of this kind have also been obtained by Z. J. Jabłoński and J. Stochel.